1
00:00:04,400 --> 00:00:07,800
Speaker 1: Welcome to text Stuff, a production from my Heart Radio.

2
00:00:12,320 --> 00:00:15,319
Speaker 1: Hey there, and welcome to tech Stuff. I'm your host,

3
00:00:15,480 --> 00:00:19,000
Speaker 1: Jonathan Strickland. I'm an executive producer with I Heart Radio

4
00:00:19,120 --> 00:00:22,680
Speaker 1: and I love all things tech and I recently had

5
00:00:22,760 --> 00:00:25,560
Speaker 1: a couple of listeners right to me and ask if

6
00:00:25,560 --> 00:00:28,960
Speaker 1: I could do an episode about solid state drives, which

7
00:00:29,040 --> 00:00:31,840
Speaker 1: is a method of data storage. So today we're going

8
00:00:31,880 --> 00:00:34,839
Speaker 1: to learn about different ways to store information with computer

9
00:00:34,920 --> 00:00:39,960
Speaker 1: systems and what makes each one special. And there are

10
00:00:40,000 --> 00:00:43,360
Speaker 1: a lot of different ways that computer scientists have created

11
00:00:43,400 --> 00:00:48,839
Speaker 1: to store information, either temporarily or you know, permanently or

12
00:00:48,920 --> 00:00:52,680
Speaker 1: semi permanently using computer systems. To go through all of

13
00:00:52,720 --> 00:00:55,960
Speaker 1: them and to explain how all of them work would

14
00:00:55,960 --> 00:00:58,680
Speaker 1: actually take a few episodes. A lot of them work

15
00:00:58,680 --> 00:01:03,880
Speaker 1: in similar ways but with different manifestations. And also a

16
00:01:03,920 --> 00:01:06,640
Speaker 1: lot of those methods are actually totally obsolete today, so

17
00:01:06,880 --> 00:01:09,679
Speaker 1: we're not gonna go over everything. Instead, we're going to

18
00:01:10,040 --> 00:01:14,319
Speaker 1: have a quick refresher on ROM, RAM, cash memory, and

19
00:01:14,360 --> 00:01:18,440
Speaker 1: then storage systems. ROM and RAM are both types of

20
00:01:18,560 --> 00:01:22,039
Speaker 1: computer memory. The purpose of computer memory is to have

21
00:01:22,120 --> 00:01:25,880
Speaker 1: a way to reference instructions quickly to run processes, and

22
00:01:25,920 --> 00:01:28,600
Speaker 1: by that I mean for the CPU to be able

23
00:01:28,640 --> 00:01:31,280
Speaker 1: to get to the information it needs. Typically, we refer

24
00:01:31,360 --> 00:01:34,240
Speaker 1: to memory as being a type of data storage that

25
00:01:34,280 --> 00:01:38,399
Speaker 1: a CPU can access directly, as opposed to permanent storage,

26
00:01:38,760 --> 00:01:42,080
Speaker 1: which must be retrieved before the CPU can access it.

27
00:01:42,440 --> 00:01:46,119
Speaker 1: A processor needs two major things to carry out tasks.

28
00:01:46,560 --> 00:01:50,040
Speaker 1: It needs a list of instructions also known as what

29
00:01:50,360 --> 00:01:54,160
Speaker 1: to do, and then data that's the stuff you're performing

30
00:01:54,160 --> 00:02:00,240
Speaker 1: operations upon. So with an absurdly simple analogy, it would

31
00:02:00,280 --> 00:02:03,280
Speaker 1: be like a teacher telling a student, Hey, I'm going

32
00:02:03,320 --> 00:02:05,600
Speaker 1: to give you some numbers, and I want you to

33
00:02:05,720 --> 00:02:10,760
Speaker 1: add those numbers together. So the student already knows the instructions, right,

34
00:02:11,000 --> 00:02:13,520
Speaker 1: They know that they are to add any numbers that

35
00:02:13,600 --> 00:02:16,480
Speaker 1: the teacher gives them. Then the teacher gives a list

36
00:02:16,520 --> 00:02:19,440
Speaker 1: of numbers, which would be the data in our example,

37
00:02:19,760 --> 00:02:22,920
Speaker 1: and the student would carry out the instructions adding them.

38
00:02:23,120 --> 00:02:26,600
Speaker 1: Computer processors do something similar, though at a speed and

39
00:02:26,680 --> 00:02:29,680
Speaker 1: level of complexity that's a little harder for us to grasp.

40
00:02:29,840 --> 00:02:33,280
Speaker 1: But without memory, the processor has nothing to draw upon

41
00:02:33,600 --> 00:02:39,240
Speaker 1: to actually do anything. Wrong. Stands for read only memory,

42
00:02:39,639 --> 00:02:43,080
Speaker 1: and as the name suggests, this is memory that the

43
00:02:43,080 --> 00:02:47,560
Speaker 1: computer can reference, but it doesn't change it or add

44
00:02:47,600 --> 00:02:51,000
Speaker 1: to it, at least not under normal circumstances. There's some

45
00:02:51,240 --> 00:02:54,880
Speaker 1: extreme exceptions, but we're not really going to get into

46
00:02:54,919 --> 00:02:57,679
Speaker 1: them here. So you can think of this like messages

47
00:02:57,680 --> 00:03:00,440
Speaker 1: that have been etched in stone, but you lack the

48
00:03:00,480 --> 00:03:03,799
Speaker 1: ability or the tools to carve in anything into stone.

49
00:03:03,880 --> 00:03:07,320
Speaker 1: So you can read these messages that already exist, but

50
00:03:07,400 --> 00:03:11,440
Speaker 1: you can't change them in any way. Typically, read only

51
00:03:11,480 --> 00:03:15,320
Speaker 1: memory contains basic instructions that a computer system needs in

52
00:03:15,440 --> 00:03:17,960
Speaker 1: order for all of its components to work together and

53
00:03:18,040 --> 00:03:21,400
Speaker 1: to boot up. So for a computer to actually be

54
00:03:21,560 --> 00:03:26,800
Speaker 1: able to detect and interact with the various components the

55
00:03:26,840 --> 00:03:31,240
Speaker 1: physical hardware that make up the computer. That's a necessary

56
00:03:31,320 --> 00:03:34,280
Speaker 1: part of ROM, and it really is just a basic

57
00:03:34,320 --> 00:03:37,240
Speaker 1: set of instructions that allow everything else to happen, like

58
00:03:37,360 --> 00:03:42,080
Speaker 1: going through the initial process of recognizing inputting output devices.

59
00:03:42,120 --> 00:03:46,160
Speaker 1: Without those instructions, the computer wouldn't do anything meaningful. It

60
00:03:46,200 --> 00:03:49,000
Speaker 1: would just be a bunch of pieces that don't actually

61
00:03:49,040 --> 00:03:54,320
Speaker 1: work together. RAM or random access memory, is kind of

62
00:03:54,360 --> 00:03:58,080
Speaker 1: like short term memory for humans. This is where a

63
00:03:58,080 --> 00:04:01,600
Speaker 1: computer can store information that's elevant to whatever the computer

64
00:04:01,680 --> 00:04:05,480
Speaker 1: is doing at that very moment. So if you're running

65
00:04:05,480 --> 00:04:09,480
Speaker 1: a program, a computer will load relevant data in RAM

66
00:04:09,520 --> 00:04:13,560
Speaker 1: for quick reference. It's kind of like how I write episodes.

67
00:04:13,920 --> 00:04:16,400
Speaker 1: I take a lot of notes and then I've got

68
00:04:16,440 --> 00:04:19,480
Speaker 1: my notes to refer to when i need to, you know,

69
00:04:19,839 --> 00:04:25,760
Speaker 1: reference something. Accessing RAM is fast generally speaking, though there

70
00:04:25,800 --> 00:04:29,840
Speaker 1: are some potential bottlenecks. I'll mention those late in this episode.

71
00:04:30,600 --> 00:04:33,920
Speaker 1: But what does the random access part of RAM mean?

72
00:04:34,680 --> 00:04:37,839
Speaker 1: It means that the processor can access the data on

73
00:04:37,880 --> 00:04:42,040
Speaker 1: a RAM chip wherever that data might be physically stored

74
00:04:42,240 --> 00:04:45,560
Speaker 1: on that chip, and that accessing any part of the

75
00:04:45,600 --> 00:04:48,720
Speaker 1: memory should generally take the same amount of time regardless

76
00:04:48,760 --> 00:04:52,320
Speaker 1: of where the data is stored. In contrast, there are

77
00:04:52,320 --> 00:04:54,960
Speaker 1: some types of storage that would require a computer to

78
00:04:55,080 --> 00:04:58,960
Speaker 1: scan through all the data recorded from the beginning of

79
00:04:59,000 --> 00:05:02,520
Speaker 1: the storage until hill it hits the relevant patch of information.

80
00:05:03,240 --> 00:05:05,719
Speaker 1: It's kind of like the difference between using a chapter

81
00:05:05,880 --> 00:05:09,239
Speaker 1: select on a DVD or Blu Ray or just fast

82
00:05:09,279 --> 00:05:11,920
Speaker 1: forward scrubbing through a movie to get to a specific scene.

83
00:05:12,360 --> 00:05:14,799
Speaker 1: If you have a DVD or Blue ray that has chapters,

84
00:05:15,120 --> 00:05:18,440
Speaker 1: you can just jump right to the relevant section and

85
00:05:18,480 --> 00:05:23,320
Speaker 1: you access that specific part of the story instantly. Without chapters,

86
00:05:23,760 --> 00:05:26,520
Speaker 1: then you have to go through the whole movie sequentially

87
00:05:26,640 --> 00:05:29,640
Speaker 1: to get to the part you actually want. RAM is

88
00:05:29,680 --> 00:05:34,240
Speaker 1: more like the chapter select approach. RAM has a limited capacity.

89
00:05:34,560 --> 00:05:36,600
Speaker 1: Now this depends on the type of RAM you've got

90
00:05:36,600 --> 00:05:41,080
Speaker 1: installing your PC or your computational device. Some machines, like

91
00:05:41,360 --> 00:05:43,920
Speaker 1: a lot of PCs, are designed in such a way

92
00:05:44,040 --> 00:05:46,719
Speaker 1: that you can upgrade RAM over time. You can add

93
00:05:46,880 --> 00:05:51,719
Speaker 1: to it and create greater RAM capacity. But even upgraded,

94
00:05:52,000 --> 00:05:54,520
Speaker 1: there will be a limit as to how much data

95
00:05:54,640 --> 00:05:58,400
Speaker 1: can exist in RAM at any given time. You can't

96
00:05:58,600 --> 00:06:03,279
Speaker 1: just keep updating RAM forever. Motherboards won't accept that. Processors

97
00:06:03,279 --> 00:06:06,719
Speaker 1: can't work with it, so there are actual limitations that

98
00:06:06,760 --> 00:06:11,719
Speaker 1: are dependent upon outside factors. Even with upgraded RAM, there

99
00:06:11,839 --> 00:06:14,000
Speaker 1: is a limit to how much data can exist in

100
00:06:14,120 --> 00:06:17,000
Speaker 1: RAM all at a given time. You can't load every

101
00:06:17,040 --> 00:06:20,320
Speaker 1: single thing from storage into RAM. It wouldn't make sense

102
00:06:20,560 --> 00:06:22,919
Speaker 1: for me to copy all of my sources word for

103
00:06:22,960 --> 00:06:26,599
Speaker 1: word in my notes, right because then my notes aren't

104
00:06:26,600 --> 00:06:29,920
Speaker 1: notes anymore. They are copies of the original sources, and

105
00:06:29,920 --> 00:06:32,560
Speaker 1: I wouldn't really be able to refer to them very quickly.

106
00:06:33,440 --> 00:06:37,039
Speaker 1: RAM is also temporary, by which I mean that the

107
00:06:37,160 --> 00:06:40,440
Speaker 1: data that is inside RAM only sticks around for as

108
00:06:40,480 --> 00:06:44,880
Speaker 1: long as the device is powered. Computer systems dump the

109
00:06:44,920 --> 00:06:49,240
Speaker 1: information and RAM whenever the computer shuts down or restarts,

110
00:06:49,279 --> 00:06:53,080
Speaker 1: so effectively the memory gets white. RAM is thus a

111
00:06:53,160 --> 00:06:56,520
Speaker 1: type of volatile memory that means it works as long

112
00:06:56,560 --> 00:06:59,159
Speaker 1: as the power is going to the system. You need

113
00:06:59,200 --> 00:07:01,760
Speaker 1: a non volu a toll form of memory, something that's

114
00:07:01,800 --> 00:07:05,320
Speaker 1: a more persistent, permanent method to store data in larger

115
00:07:05,400 --> 00:07:07,600
Speaker 1: volumes if you want to be able to access it

116
00:07:07,960 --> 00:07:12,920
Speaker 1: in subsequent sessions. ROM is non volatile, but then again,

117
00:07:12,920 --> 00:07:16,600
Speaker 1: it's also unchangeable, so that doesn't do you any good either.

118
00:07:16,680 --> 00:07:19,240
Speaker 1: You need something that you can actually update that is

119
00:07:19,280 --> 00:07:21,480
Speaker 1: also non volatile if you want to be able to

120
00:07:21,520 --> 00:07:26,800
Speaker 1: hold onto data between sessions. Before I move on to that, though,

121
00:07:27,040 --> 00:07:30,400
Speaker 1: I should also mention cash memory c a c ch

122
00:07:30,520 --> 00:07:36,280
Speaker 1: E memory. This allows processors to access specific, frequently referred

123
00:07:36,320 --> 00:07:41,000
Speaker 1: to data at very fast speeds, faster than RAM. It

124
00:07:41,040 --> 00:07:44,800
Speaker 1: has less capacity for storage than RAM does, but it

125
00:07:44,800 --> 00:07:46,920
Speaker 1: can hold stuff that the processor is going to need

126
00:07:46,960 --> 00:07:49,960
Speaker 1: to refer to a lot in order to complete whatever

127
00:07:49,960 --> 00:07:53,400
Speaker 1: the task at hand happens to be. RAM capacity tends

128
00:07:53,440 --> 00:07:56,040
Speaker 1: to be in the gigabyte range these days, but CASH

129
00:07:56,080 --> 00:07:58,760
Speaker 1: tends to be much lower, like in the megabyte range,

130
00:07:59,280 --> 00:08:03,080
Speaker 1: and just for the purposes of clarity, A byte is

131
00:08:03,120 --> 00:08:06,200
Speaker 1: a unit of information that's equal to eight bits, and

132
00:08:06,280 --> 00:08:09,559
Speaker 1: a bit is a piece of binary information a zero

133
00:08:09,760 --> 00:08:13,840
Speaker 1: or a one. A megabyte is essentially one million bytes,

134
00:08:13,920 --> 00:08:18,040
Speaker 1: and a gigabyte is essentially one billion bytes. A terabyte

135
00:08:18,080 --> 00:08:21,720
Speaker 1: is essentially one trillion bytes. If you were to look

136
00:08:21,760 --> 00:08:24,960
Speaker 1: at a computer motherboard, you would see the CPU or

137
00:08:25,040 --> 00:08:28,920
Speaker 1: central processing unit, which is what executes the programs, and

138
00:08:29,000 --> 00:08:32,560
Speaker 1: physically closest to the CPU would be the cash memory,

139
00:08:32,720 --> 00:08:35,520
Speaker 1: which holds data that's going to be referenced frequently by

140
00:08:35,559 --> 00:08:39,360
Speaker 1: the CPU. Next would be the RAM, So the CPU

141
00:08:39,400 --> 00:08:42,200
Speaker 1: would check for information in cash memory first to see

142
00:08:42,200 --> 00:08:44,520
Speaker 1: if it's there. If not, it would send a fetch

143
00:08:44,520 --> 00:08:47,560
Speaker 1: request for information stored in RAM to see if it's there.

144
00:08:48,200 --> 00:08:50,320
Speaker 1: And if the data isn't there, then the CPU has

145
00:08:50,360 --> 00:08:52,480
Speaker 1: to send out a request to fetch data from non

146
00:08:52,600 --> 00:08:57,040
Speaker 1: volatile storage. Non Volatile memory is necessary if you want

147
00:08:57,080 --> 00:09:00,240
Speaker 1: to save data for longer than the immediate present. The

148
00:09:00,280 --> 00:09:03,520
Speaker 1: tradeoff is it takes a processor a little bit longer

149
00:09:03,600 --> 00:09:07,600
Speaker 1: to access that data. So in my notes example, let's

150
00:09:07,640 --> 00:09:10,000
Speaker 1: say that I'm doing this episode and there's something I

151
00:09:10,040 --> 00:09:12,280
Speaker 1: wanted to talk about, but I didn't write it down

152
00:09:12,280 --> 00:09:15,240
Speaker 1: in my notes. I do happen to know, however, that

153
00:09:15,320 --> 00:09:18,520
Speaker 1: it's in one of the large, dusty books that surround

154
00:09:18,559 --> 00:09:22,200
Speaker 1: me at all times. I am cursed with them. So

155
00:09:22,440 --> 00:09:24,400
Speaker 1: I would take a book aside, and then I would

156
00:09:24,400 --> 00:09:27,079
Speaker 1: start searching through the book to find the relevant information.

157
00:09:27,240 --> 00:09:29,520
Speaker 1: And this takes a bit longer than just glancing at

158
00:09:29,520 --> 00:09:32,160
Speaker 1: my notes would. And that's kind of what it's like

159
00:09:32,240 --> 00:09:35,400
Speaker 1: for a computer to reference information that's stored on a

160
00:09:35,480 --> 00:09:39,160
Speaker 1: hard drive or solid state drive. When I was growing up,

161
00:09:39,400 --> 00:09:43,120
Speaker 1: my family's first real computer was an Apple to Eat,

162
00:09:43,240 --> 00:09:46,600
Speaker 1: and that computer did not have a hard drive. Instead,

163
00:09:47,080 --> 00:09:50,040
Speaker 1: you would save information onto five and a quarter inch

164
00:09:50,240 --> 00:09:53,880
Speaker 1: floppy disc ets the computer had a disk drive. You

165
00:09:53,880 --> 00:09:56,640
Speaker 1: would slide the floppy disk into the disk drive and

166
00:09:56,679 --> 00:09:59,280
Speaker 1: then you could access whatever information was stored on it,

167
00:09:59,400 --> 00:10:02,600
Speaker 1: or you could save information to it. If the computer

168
00:10:02,640 --> 00:10:05,560
Speaker 1: needed to reference something from the disk, everything would be

169
00:10:05,600 --> 00:10:08,400
Speaker 1: pretty much put on hold while the computer searched the

170
00:10:08,440 --> 00:10:12,079
Speaker 1: disks contents for the specific information, then pull it up

171
00:10:12,160 --> 00:10:15,240
Speaker 1: loaded into RAM, and then the computer program could continue.

172
00:10:15,679 --> 00:10:20,040
Speaker 1: This process is particularly noticeable if you're running something really

173
00:10:20,200 --> 00:10:25,040
Speaker 1: process or intensive like computer game. More complicated games such

174
00:10:25,080 --> 00:10:28,080
Speaker 1: as those that have like really nice graphics, take up

175
00:10:28,120 --> 00:10:31,440
Speaker 1: a lot of space. From a data perspective, the developers

176
00:10:31,440 --> 00:10:34,200
Speaker 1: will typically design a game so that the computer running

177
00:10:34,240 --> 00:10:37,880
Speaker 1: the game will load chunks of the game into its memory,

178
00:10:38,040 --> 00:10:41,480
Speaker 1: but if you navigate to a new chunk, the computer

179
00:10:41,559 --> 00:10:45,120
Speaker 1: has to reference the information in storage and then update everything,

180
00:10:45,160 --> 00:10:48,760
Speaker 1: and that leads to the dreaded loading screen, and developers

181
00:10:48,760 --> 00:10:50,480
Speaker 1: have found a lot of different ways to kind of

182
00:10:50,520 --> 00:10:52,880
Speaker 1: deal with this. A common one was to put in

183
00:10:52,880 --> 00:10:55,480
Speaker 1: a loading screen whenever you would go through a door

184
00:10:55,679 --> 00:10:59,120
Speaker 1: that represented a major change of environment, such as if

185
00:10:59,120 --> 00:11:01,600
Speaker 1: you were to go from the outside world of the

186
00:11:01,640 --> 00:11:05,200
Speaker 1: game and enter the inside world, like going into a castle.

187
00:11:05,920 --> 00:11:08,720
Speaker 1: Between being outside and inside, you know, when you would

188
00:11:08,760 --> 00:11:11,680
Speaker 1: hit that door and you'd say open, you'd get treated

189
00:11:11,720 --> 00:11:14,680
Speaker 1: to a loading screen. So part of what we're going

190
00:11:14,720 --> 00:11:17,720
Speaker 1: to learn about today is why loading screens are even

191
00:11:17,760 --> 00:11:20,160
Speaker 1: a thing and what type of storage results in different

192
00:11:20,160 --> 00:11:24,920
Speaker 1: weight times. And let's start with hard disk drives a ka,

193
00:11:25,040 --> 00:11:29,439
Speaker 1: the platter based drives. Alright, So back in the day,

194
00:11:29,559 --> 00:11:32,520
Speaker 1: we used to store data on either floppy disks or

195
00:11:32,640 --> 00:11:35,800
Speaker 1: hard disks. Although floppy disks are really a thing of

196
00:11:35,840 --> 00:11:38,520
Speaker 1: the past at this point, unless you're using a truly

197
00:11:38,600 --> 00:11:43,080
Speaker 1: old computer system, like a legacy computer system. Hard disks

198
00:11:43,120 --> 00:11:47,160
Speaker 1: actually predate floppy disks, and we didn't call them hard

199
00:11:47,200 --> 00:11:51,040
Speaker 1: disks originally because there was no floppy disk to refer to.

200
00:11:51,080 --> 00:11:53,679
Speaker 1: You wouldn't call one without the other, right, there can

201
00:11:53,679 --> 00:11:56,960
Speaker 1: be no good without evil. Well, originally we called these

202
00:11:57,160 --> 00:12:02,440
Speaker 1: fixed disks, or sometimes we even were to them as Winchesters.

203
00:12:02,559 --> 00:12:04,640
Speaker 1: And no, it wasn't a pair of brothers who went

204
00:12:04,679 --> 00:12:09,360
Speaker 1: around attacking supernatural bad guys. In this case, the term

205
00:12:09,400 --> 00:12:14,240
Speaker 1: Winchester actually came from IBM. It was IBM computer scientists

206
00:12:14,240 --> 00:12:18,320
Speaker 1: who pioneered the design of the platter based hard drive

207
00:12:18,640 --> 00:12:22,760
Speaker 1: back in the nineteen fifties, and the code name was Winchester.

208
00:12:23,440 --> 00:12:26,640
Speaker 1: But then once floppy disks came along, folks would refer

209
00:12:26,720 --> 00:12:29,880
Speaker 1: to fixed discs as hard disks. And then you had

210
00:12:29,880 --> 00:12:33,360
Speaker 1: the differentiation. You had the floppy disks, which were external,

211
00:12:33,520 --> 00:12:35,280
Speaker 1: then you would insert them into a drive and then

212
00:12:35,360 --> 00:12:37,840
Speaker 1: remove them when you were done, and you had hard

213
00:12:37,840 --> 00:12:42,720
Speaker 1: disks which stayed inside the computer. So hard disks are

214
00:12:43,040 --> 00:12:46,960
Speaker 1: disc shaped there around with a hub or or hole

215
00:12:47,000 --> 00:12:52,560
Speaker 1: in the middle, and they are contained within a sealed container,

216
00:12:53,000 --> 00:12:56,960
Speaker 1: typically made of something like aluminum. And the reason why

217
00:12:57,240 --> 00:13:00,839
Speaker 1: is because aluminum is a material that is non magnetic

218
00:13:01,160 --> 00:13:05,239
Speaker 1: under normal conditions. If you went to truly extreme conditions,

219
00:13:05,760 --> 00:13:09,280
Speaker 1: you could magnetize aluminum, but it would be well outside

220
00:13:09,640 --> 00:13:13,800
Speaker 1: the conditions you would find someone's personal computer in. So

221
00:13:14,160 --> 00:13:17,560
Speaker 1: old hard discs could only hold a few megabytes worth

222
00:13:17,559 --> 00:13:21,040
Speaker 1: of data and they measured like twenty inches in diameter.

223
00:13:21,160 --> 00:13:24,080
Speaker 1: They were huge, you know. The much later there would

224
00:13:24,080 --> 00:13:26,200
Speaker 1: be closer to three and a half inches in diameter.

225
00:13:26,679 --> 00:13:30,760
Speaker 1: So typically hard disk drives actually have stacks of discs.

226
00:13:30,800 --> 00:13:33,520
Speaker 1: It's not just a single disc like a single platter,

227
00:13:33,840 --> 00:13:37,240
Speaker 1: it's actually a stack of them, and each platter in

228
00:13:37,280 --> 00:13:41,400
Speaker 1: that stack is separated by a small amount of space,

229
00:13:41,800 --> 00:13:46,040
Speaker 1: so there's actually free space between each stack. If you

230
00:13:46,080 --> 00:13:47,800
Speaker 1: think of one, two, and three, you've got a little

231
00:13:47,800 --> 00:13:51,400
Speaker 1: bit of space between each of those. And that's really

232
00:13:51,440 --> 00:13:54,199
Speaker 1: important and I'll get into that in a second. But

233
00:13:54,640 --> 00:13:58,840
Speaker 1: floppy disks are a disc of thin plastic that has

234
00:13:58,880 --> 00:14:02,400
Speaker 1: a coding of magnetic material on top of it, and

235
00:14:02,440 --> 00:14:07,920
Speaker 1: the plastic disc is inside an envelope or disket made

236
00:14:08,000 --> 00:14:11,360
Speaker 1: of thicker plastic and there have been several sizes of

237
00:14:11,360 --> 00:14:14,520
Speaker 1: floppy discs over the years. There were eight inch discs,

238
00:14:14,600 --> 00:14:16,599
Speaker 1: five and a quarter inch discs like my Apple to

239
00:14:16,720 --> 00:14:19,440
Speaker 1: e had, and then three and a half inch diskts,

240
00:14:19,640 --> 00:14:24,080
Speaker 1: which my IBM compatible computer used. The eight and the

241
00:14:24,080 --> 00:14:27,280
Speaker 1: five and aquarre inch discs were pretty thin. They were

242
00:14:27,280 --> 00:14:30,880
Speaker 1: made out of a thinner plastic material and that gave

243
00:14:31,440 --> 00:14:35,840
Speaker 1: us the name floppy disc because they were flexible, though

244
00:14:36,720 --> 00:14:38,800
Speaker 1: you were not supposed to bend them in any way

245
00:14:38,840 --> 00:14:41,840
Speaker 1: that would possibly ruin everything. In fact, if you really

246
00:14:41,960 --> 00:14:45,720
Speaker 1: bent it, you had just destroyed that disk. Uh. This

247
00:14:45,840 --> 00:14:47,960
Speaker 1: was a piece of information that would have been useful

248
00:14:48,000 --> 00:14:50,440
Speaker 1: to a lot of people back in the early eighties

249
00:14:50,480 --> 00:14:54,680
Speaker 1: when they weren't aware that floppy did not mean you

250
00:14:54,680 --> 00:14:58,400
Speaker 1: can fold it. But the terminology would become more confusing

251
00:14:58,480 --> 00:15:01,440
Speaker 1: later on when three and a half inch discs, which

252
00:15:01,440 --> 00:15:04,240
Speaker 1: are in a much thicker plastic case one that is

253
00:15:04,280 --> 00:15:08,960
Speaker 1: not flexible, When those came around, it confused everything because

254
00:15:08,960 --> 00:15:11,160
Speaker 1: those discs weren't floppy like the five and a quarter

255
00:15:11,280 --> 00:15:14,240
Speaker 1: inch ones, So some folks would mistakenly refer to three

256
00:15:14,280 --> 00:15:17,600
Speaker 1: and a half inch discs as hard disks, but they

257
00:15:17,600 --> 00:15:20,400
Speaker 1: were still a type of external storage. You would insert

258
00:15:20,400 --> 00:15:22,640
Speaker 1: a floppy disk into a disk drive, you would read

259
00:15:22,720 --> 00:15:24,640
Speaker 1: or write to that disk, and then you could inject

260
00:15:24,720 --> 00:15:27,360
Speaker 1: the disc and replace it with another one. And that's

261
00:15:27,360 --> 00:15:29,840
Speaker 1: how our old Apple to E worked. If you were

262
00:15:29,840 --> 00:15:32,040
Speaker 1: to write a page of text, you would save that

263
00:15:32,160 --> 00:15:35,880
Speaker 1: page to a floppy disk for later retrieval because the

264
00:15:35,880 --> 00:15:39,360
Speaker 1: computer had no way to store information on it permanently.

265
00:15:40,240 --> 00:15:44,160
Speaker 1: Later on, c d s or compact discs would largely

266
00:15:44,200 --> 00:15:47,880
Speaker 1: replace the need for floppy disks, particularly when computers began

267
00:15:47,920 --> 00:15:50,880
Speaker 1: to include drives that could read or write to c

268
00:15:51,080 --> 00:15:53,840
Speaker 1: d s. But by then we were also looking at

269
00:15:53,840 --> 00:15:56,440
Speaker 1: computers that had internal storage in the form of a

270
00:15:56,520 --> 00:15:59,960
Speaker 1: hard disk drive. And really the hard disk and floppy

271
00:16:00,080 --> 00:16:03,040
Speaker 1: disk systems are fairly similar to each other, so rather

272
00:16:03,080 --> 00:16:06,040
Speaker 1: than explain how each one works, I'll focus on hard

273
00:16:06,080 --> 00:16:08,720
Speaker 1: disks so that we can contrast that with solid state

274
00:16:08,800 --> 00:16:12,280
Speaker 1: drives in a little bit. Before we get into any

275
00:16:12,320 --> 00:16:23,200
Speaker 1: of that, however, let's take a quick break. The first

276
00:16:23,240 --> 00:16:26,360
Speaker 1: thing to get into our heads is that hard disk

277
00:16:26,520 --> 00:16:31,520
Speaker 1: drives and floppy drives for that matter, are electro mechanical systems,

278
00:16:32,080 --> 00:16:35,480
Speaker 1: so they have moving parts and if you were able

279
00:16:35,520 --> 00:16:39,000
Speaker 1: to see through a computer, you know, Superman style, and

280
00:16:39,080 --> 00:16:41,120
Speaker 1: you were able to see it's hard drive in motion.

281
00:16:41,640 --> 00:16:44,640
Speaker 1: You might think it bears some resemblance to how a

282
00:16:44,800 --> 00:16:48,520
Speaker 1: turntable plays the tracks on a vinyl record, And there

283
00:16:48,640 --> 00:16:53,640
Speaker 1: is some similarity there, but only to a very superficial point. See,

284
00:16:53,840 --> 00:16:57,880
Speaker 1: a vinyl record has physical grooves in it. The groove

285
00:16:58,000 --> 00:17:00,560
Speaker 1: is a three dimensional groove with a little ridges and

286
00:17:00,680 --> 00:17:03,880
Speaker 1: dips and edges, and the stylus or needle of the

287
00:17:03,920 --> 00:17:07,960
Speaker 1: record player vibrates as it travels along this groove, and

288
00:17:07,960 --> 00:17:11,439
Speaker 1: those vibrations passed to a piece of electric crystal or

289
00:17:11,440 --> 00:17:15,720
Speaker 1: a tiny electromagnet, and that transforms the kinetic energy the

290
00:17:15,800 --> 00:17:20,119
Speaker 1: energy get movement into electrical energy, and that electrical signal

291
00:17:20,240 --> 00:17:23,840
Speaker 1: then passes on to amplifiers that boost that signal. That

292
00:17:23,920 --> 00:17:26,960
Speaker 1: then goes on to speakers and it plays out as

293
00:17:27,000 --> 00:17:30,439
Speaker 1: the sound that's on the record. Hard disc doesn't have

294
00:17:30,760 --> 00:17:34,440
Speaker 1: a physical groove in it. Instead, it's a platter made

295
00:17:34,440 --> 00:17:38,680
Speaker 1: out of something like ceramic glass or an aluminum alloy,

296
00:17:39,000 --> 00:17:42,240
Speaker 1: and it has a mirror like finish. In fact, it's

297
00:17:42,320 --> 00:17:47,840
Speaker 1: highly reflective. The disc has ferromagnetic particles bonded to it.

298
00:17:48,240 --> 00:17:52,159
Speaker 1: These particles, if they are exposed to a magnetic field

299
00:17:52,200 --> 00:17:55,040
Speaker 1: become magnetized themselves, and they will hold on to that

300
00:17:55,119 --> 00:17:58,840
Speaker 1: magnetic property. So if you create a system where you

301
00:17:58,880 --> 00:18:04,000
Speaker 1: give meaning to the specific magnetic orientation of domains of

302
00:18:04,080 --> 00:18:07,720
Speaker 1: particles domains or sectors or regions of these particles on

303
00:18:07,760 --> 00:18:11,920
Speaker 1: the platter, you can designate that as stuff like zeros

304
00:18:12,040 --> 00:18:15,200
Speaker 1: and ones. For example, you could say that a domain

305
00:18:15,240 --> 00:18:18,600
Speaker 1: that is magnetized so it aligns in the north direction

306
00:18:19,160 --> 00:18:21,560
Speaker 1: is a one, and a domain that's aligned in the

307
00:18:21,680 --> 00:18:25,040
Speaker 1: south direction is a zero. And then by applying a

308
00:18:25,080 --> 00:18:28,760
Speaker 1: precise magnetic fluctuation to the domains, you could arrange them

309
00:18:28,800 --> 00:18:33,119
Speaker 1: into meaningful representations of information. So with a hard disk drive,

310
00:18:33,560 --> 00:18:36,320
Speaker 1: you do in fact have a disk, or more likely

311
00:18:36,600 --> 00:18:40,080
Speaker 1: several disks or platters in a stack, and there is

312
00:18:40,119 --> 00:18:42,720
Speaker 1: a hole or hub in the center of these disks,

313
00:18:43,240 --> 00:18:46,760
Speaker 1: and those fit around a spindle. The spindle has a

314
00:18:46,800 --> 00:18:50,320
Speaker 1: motor that can spend the disc super fast. I'll get

315
00:18:50,320 --> 00:18:52,679
Speaker 1: into how fast in a second. Then you've got a

316
00:18:52,720 --> 00:18:56,480
Speaker 1: mechanical arm and this has the little read right heads

317
00:18:56,680 --> 00:18:59,639
Speaker 1: and those are transducers. These act kind of like the

318
00:18:59,720 --> 00:19:04,120
Speaker 1: knee doll on a turntable, but there have their own

319
00:19:04,119 --> 00:19:07,520
Speaker 1: special properties, and this arm can move from the inner

320
00:19:07,600 --> 00:19:09,399
Speaker 1: edge of the disc to the outer edge in a

321
00:19:09,480 --> 00:19:12,119
Speaker 1: fraction of a second. In fact, it would not be

322
00:19:12,200 --> 00:19:14,320
Speaker 1: unusual to have one of these be able to move

323
00:19:14,440 --> 00:19:18,720
Speaker 1: between those two edges fifty times per second. The arm

324
00:19:18,760 --> 00:19:22,919
Speaker 1: itself is split so that the right head, as in

325
00:19:22,960 --> 00:19:25,479
Speaker 1: the w R I T E head, the head that

326
00:19:25,600 --> 00:19:29,199
Speaker 1: writes data to the disc, fits on one side of

327
00:19:29,200 --> 00:19:32,479
Speaker 1: the platter, and the read head that reads information off

328
00:19:32,480 --> 00:19:35,320
Speaker 1: the disc can fit on the other side of the platter.

329
00:19:35,600 --> 00:19:39,680
Speaker 1: So the platter will spend between these two heads and

330
00:19:40,160 --> 00:19:44,080
Speaker 1: they will be separated from that platter by just a tiny, tiny,

331
00:19:44,119 --> 00:19:46,960
Speaker 1: tiny amount of space. This is one of those points

332
00:19:46,960 --> 00:19:50,520
Speaker 1: where our vinyl record analogy really breaks down, because it

333
00:19:50,560 --> 00:19:53,119
Speaker 1: would be like you would have a stylus or needle

334
00:19:53,280 --> 00:19:55,679
Speaker 1: on either side of a record as it plays on

335
00:19:55,680 --> 00:19:59,239
Speaker 1: the turntable, and that just doesn't happen. Now. Typically the

336
00:19:59,320 --> 00:20:03,159
Speaker 1: arms motion controlled with electro magnets. Then you are likely

337
00:20:03,240 --> 00:20:05,800
Speaker 1: dealing with a stack of discs, so you would also

338
00:20:05,840 --> 00:20:09,360
Speaker 1: be working with a stack of read write heads mounted

339
00:20:09,400 --> 00:20:13,040
Speaker 1: on this arm. You would have one pair of read

340
00:20:13,080 --> 00:20:17,280
Speaker 1: write head transducers for every disc on the stack, and

341
00:20:17,320 --> 00:20:20,080
Speaker 1: the arms would be separated like timees on a fork,

342
00:20:20,680 --> 00:20:23,879
Speaker 1: so they can fit between those spinning disks, and it

343
00:20:23,920 --> 00:20:26,480
Speaker 1: gets pretty snug in those hard drives. So if you

344
00:20:26,520 --> 00:20:28,959
Speaker 1: had three platters in your hard drive, you would have

345
00:20:29,040 --> 00:20:32,760
Speaker 1: six read right heads right, one read and one right

346
00:20:32,840 --> 00:20:36,639
Speaker 1: head for each of the three platters. A transducer, by

347
00:20:36,640 --> 00:20:40,280
Speaker 1: the way, is a type of electronic device that converts

348
00:20:40,520 --> 00:20:44,240
Speaker 1: one form of energy into another form of energy, and

349
00:20:44,280 --> 00:20:46,960
Speaker 1: there's a lot of stuff that falls into that category.

350
00:20:47,040 --> 00:20:50,960
Speaker 1: It's a broad category. So a microphone has a transducer.

351
00:20:51,000 --> 00:20:55,040
Speaker 1: It converts the kinetic energy from air pressure fluctuations a

352
00:20:55,160 --> 00:20:59,520
Speaker 1: k a. Sound into electrical signals. A speaker does the

353
00:20:59,560 --> 00:21:02,400
Speaker 1: same thing, but in the opposite direction. It takes electrical

354
00:21:02,440 --> 00:21:06,280
Speaker 1: signals and converts those into kinetic energy by driving the

355
00:21:06,400 --> 00:21:09,480
Speaker 1: diaphragm of a speaker to create fluctuations and air pressure,

356
00:21:09,640 --> 00:21:13,680
Speaker 1: and we experience that a sound. A digital thermometer converts

357
00:21:13,720 --> 00:21:16,760
Speaker 1: thermal energy into electrical energy, and then that can be

358
00:21:16,840 --> 00:21:21,879
Speaker 1: measured and displayed on a little screen. The transducers in

359
00:21:21,920 --> 00:21:25,800
Speaker 1: a hard disk drives read right head convert electrical energy

360
00:21:25,920 --> 00:21:29,840
Speaker 1: into magnetic energy. The arm positions the read right head

361
00:21:29,880 --> 00:21:34,359
Speaker 1: at a very specific point along the spinning platter, and

362
00:21:34,640 --> 00:21:37,480
Speaker 1: those platters are spinning at like a hundred seventy miles

363
00:21:37,480 --> 00:21:41,120
Speaker 1: per hour two d seventy two kilometers per hour. They

364
00:21:41,119 --> 00:21:44,119
Speaker 1: could be spinning at a rate of thirty six hundred RPMs.

365
00:21:44,440 --> 00:21:47,320
Speaker 1: Those are the old slow hard disk drives. If you

366
00:21:47,320 --> 00:21:53,360
Speaker 1: can believe it, pms ten thousand revolutions per minute. It's

367
00:21:53,400 --> 00:21:56,200
Speaker 1: incredible how fast they spend. And the transducer on these

368
00:21:56,240 --> 00:22:00,600
Speaker 1: read right heads applies a magnetic fluctuation to that spinning disk,

369
00:22:01,160 --> 00:22:05,800
Speaker 1: aligning magnetic particles either in a north or south orientation

370
00:22:05,880 --> 00:22:11,200
Speaker 1: to indicate those ones and zeros recording information in binary data. Now,

371
00:22:11,200 --> 00:22:14,920
Speaker 1: to read data, a transducer works more or less in reverse.

372
00:22:15,200 --> 00:22:18,400
Speaker 1: The arm moves out to a certain distance from the

373
00:22:18,560 --> 00:22:21,560
Speaker 1: edge of the disk as the disc spins up, and

374
00:22:21,600 --> 00:22:25,560
Speaker 1: the moving magnetic particles traveling below the read right head

375
00:22:25,920 --> 00:22:29,320
Speaker 1: induce an electrical signal to flow through the head, which

376
00:22:29,359 --> 00:22:32,640
Speaker 1: then can be sent on to a processor. So instead

377
00:22:32,640 --> 00:22:37,280
Speaker 1: of making a magnetic flux affect the platter, the actual

378
00:22:37,400 --> 00:22:41,560
Speaker 1: magnetic field that is generated by the particles on the

379
00:22:41,600 --> 00:22:46,960
Speaker 1: platter affect the transducer. It's a very elegant kind of solution. Now,

380
00:22:47,000 --> 00:22:49,680
Speaker 1: The data on a hard disk falls into areas known

381
00:22:49,720 --> 00:22:52,960
Speaker 1: as sectors and tracks. You can think of a track

382
00:22:53,400 --> 00:22:56,760
Speaker 1: as a concentric circle, sort of like an archery target.

383
00:22:57,320 --> 00:22:59,680
Speaker 1: These circles get larger as you get to the outer edge.

384
00:22:59,680 --> 00:23:02,760
Speaker 1: It also means that they travel at a different speed.

385
00:23:03,040 --> 00:23:05,119
Speaker 1: The outer edge of a record travels at a faster

386
00:23:05,240 --> 00:23:09,160
Speaker 1: speed than the inner edge of a record, which doesn't

387
00:23:09,160 --> 00:23:10,840
Speaker 1: seem to make sense at first because you think it's

388
00:23:10,840 --> 00:23:13,240
Speaker 1: all rotating at the same rate. But you have to

389
00:23:13,240 --> 00:23:17,479
Speaker 1: remember that outer edge represents a further distance, so the

390
00:23:17,520 --> 00:23:20,240
Speaker 1: outer edge is going further in the same amount of

391
00:23:20,280 --> 00:23:23,119
Speaker 1: time as the inner edge, which means it has to

392
00:23:23,160 --> 00:23:28,879
Speaker 1: be traveling faster. So so sectors are like wedges within

393
00:23:29,000 --> 00:23:32,520
Speaker 1: those concentric circles. If you think of the platter as

394
00:23:32,560 --> 00:23:35,959
Speaker 1: like a pie, the sectors would be the slices of

395
00:23:36,040 --> 00:23:43,119
Speaker 1: pie along these concentric circles. Mm hmm pie. Tracks are

396
00:23:43,240 --> 00:23:47,160
Speaker 1: numbered with zero being the closest to the outermost edge

397
00:23:47,160 --> 00:23:50,280
Speaker 1: of the disc, and then counting upward from there until

398
00:23:50,320 --> 00:23:52,040
Speaker 1: you get all the way to the inner part of

399
00:23:52,080 --> 00:23:55,359
Speaker 1: the disc. Sectors can hold a set number of bites,

400
00:23:55,400 --> 00:23:59,320
Speaker 1: like five twelve bites. That's not very many bites. At all,

401
00:23:59,800 --> 00:24:02,679
Speaker 1: they have a limited capacity. So in addition, the computer

402
00:24:02,760 --> 00:24:07,720
Speaker 1: typically groups certain sectors together into what are called clusters.

403
00:24:07,760 --> 00:24:10,679
Speaker 1: The computer has to keep track of which sectors in

404
00:24:10,840 --> 00:24:14,359
Speaker 1: which tracks have free space in them before saving a

405
00:24:14,480 --> 00:24:17,520
Speaker 1: file to the hard drive. So when you're looking at

406
00:24:17,560 --> 00:24:20,360
Speaker 1: a file management system and you see you have limited

407
00:24:20,359 --> 00:24:23,359
Speaker 1: space on a computer device that has hard disk drive,

408
00:24:23,840 --> 00:24:27,280
Speaker 1: you know that that actually corresponds with actual available physical

409
00:24:27,400 --> 00:24:31,320
Speaker 1: space on the platters themselves. Also, one way some machines

410
00:24:31,440 --> 00:24:36,040
Speaker 1: organized hard drive platters is in cylinders. So we've got

411
00:24:36,040 --> 00:24:38,960
Speaker 1: our stack of hard drive platters right there, all one

412
00:24:39,080 --> 00:24:41,320
Speaker 1: round top of the other, separated by a thin amount

413
00:24:41,359 --> 00:24:45,439
Speaker 1: of space. If you were to look at one track,

414
00:24:45,560 --> 00:24:49,480
Speaker 1: one concentric circle on the top platter, you could imagine

415
00:24:49,680 --> 00:24:53,760
Speaker 1: that the corresponding concentric circle on platters two and three

416
00:24:54,240 --> 00:24:57,040
Speaker 1: are grouped with that same circle on the top platter,

417
00:24:57,720 --> 00:25:00,680
Speaker 1: And then you've got yourself a cylinder for um platter

418
00:25:00,760 --> 00:25:04,200
Speaker 1: one down to platter three. They'll remember, these platterers are

419
00:25:04,240 --> 00:25:07,359
Speaker 1: not in contact with one another, so it's a virtual cylinder.

420
00:25:07,760 --> 00:25:12,040
Speaker 1: Not all computer systems use this method for organizing information

421
00:25:12,080 --> 00:25:15,879
Speaker 1: on a hard disc. However, ideally, files get stored on

422
00:25:16,080 --> 00:25:20,960
Speaker 1: adjacent sectors within a cluster, or adjacent clusters or clusters

423
00:25:20,960 --> 00:25:24,080
Speaker 1: that are vertically aligned within a cylinder. In other words,

424
00:25:24,240 --> 00:25:28,120
Speaker 1: the group together kind of geographically. But as hard disk

425
00:25:28,240 --> 00:25:31,720
Speaker 1: drive space fills up, that just might not be possible.

426
00:25:31,760 --> 00:25:34,520
Speaker 1: You might not have enough adjacent sectors to be able

427
00:25:34,520 --> 00:25:37,040
Speaker 1: to do that, and then it becomes necessary for the

428
00:25:37,119 --> 00:25:41,199
Speaker 1: drive to store sections of a file's data into different

429
00:25:41,280 --> 00:25:44,560
Speaker 1: sectors on the hard disk itself. The system keeps track

430
00:25:44,600 --> 00:25:47,119
Speaker 1: of where all these bits of the files are, but

431
00:25:47,200 --> 00:25:49,280
Speaker 1: it does mean that the transducer has to move around

432
00:25:49,280 --> 00:25:51,840
Speaker 1: a lot more to read all the relevant data stored

433
00:25:51,920 --> 00:25:54,640
Speaker 1: on the hard drive in order to send that files

434
00:25:54,680 --> 00:25:57,639
Speaker 1: information to the CPU, and that's something that can cause

435
00:25:57,720 --> 00:26:00,919
Speaker 1: a little tiny delay. I mentioned and that this is

436
00:26:01,080 --> 00:26:06,159
Speaker 1: an incredibly precise technology, which is extra impressive considering the

437
00:26:06,240 --> 00:26:09,440
Speaker 1: speeds we're talking about with regard to both the arms

438
00:26:09,480 --> 00:26:13,639
Speaker 1: movement and the revolutions per minute of the platters. But

439
00:26:13,680 --> 00:26:17,199
Speaker 1: the word precise, ironically doesn't give you an idea of

440
00:26:17,200 --> 00:26:21,520
Speaker 1: what I'm talking about with modern hard disk drives. So again,

441
00:26:21,600 --> 00:26:25,680
Speaker 1: let's imagine the grooves on a vinyl record album. Those

442
00:26:25,680 --> 00:26:29,720
Speaker 1: grooves are typically between point zero four millimeters and point

443
00:26:29,840 --> 00:26:34,800
Speaker 1: zero eight millimeters wide, or between forty to eighty microns wide.

444
00:26:35,320 --> 00:26:38,400
Speaker 1: The bands of information on a hard disc can measure

445
00:26:38,480 --> 00:26:43,159
Speaker 1: less than one hundred nanometers in width. A nanometer is

446
00:26:43,240 --> 00:26:47,040
Speaker 1: one billionth of a meter, a micron is just one

447
00:26:47,160 --> 00:26:50,240
Speaker 1: millionth of a meter, and a human hair typically has

448
00:26:50,280 --> 00:26:54,600
Speaker 1: a width of between eighty thousand to one hundred thousand nanometers.

449
00:26:54,960 --> 00:26:59,000
Speaker 1: So imagine that these bands of information are measuring less

450
00:26:59,000 --> 00:27:03,440
Speaker 1: than a hundred meters wide. That is incredible. In fact,

451
00:27:03,480 --> 00:27:06,119
Speaker 1: if you were to measure one inch in from the

452
00:27:06,200 --> 00:27:08,879
Speaker 1: edge of a disk, you could fit around three hundred

453
00:27:08,880 --> 00:27:11,840
Speaker 1: thousand tracts of information side by side in that space.

454
00:27:12,160 --> 00:27:14,960
Speaker 1: Based on that with we refer to the amount of

455
00:27:15,040 --> 00:27:17,600
Speaker 1: data that a hard disc can store on its physical

456
00:27:17,640 --> 00:27:23,399
Speaker 1: structure as aerial density, not aerial like doing tricks on

457
00:27:23,440 --> 00:27:26,480
Speaker 1: the trapeze, aerial as an a R E A L

458
00:27:27,080 --> 00:27:31,399
Speaker 1: part of area, and these days that that can be

459
00:27:31,520 --> 00:27:34,720
Speaker 1: greater than a ter a bit per square inch, and

460
00:27:34,760 --> 00:27:37,000
Speaker 1: a terra bit, like I said, as a trillion bits,

461
00:27:37,040 --> 00:27:42,120
Speaker 1: that's a hundred twenty five billion bytes. By comparison, IBM

462
00:27:42,200 --> 00:27:45,879
Speaker 1: S three fifty Raymack disc way back in nineteen fifty

463
00:27:45,960 --> 00:27:49,560
Speaker 1: six could only hold two thousand bits per square inch.

464
00:27:50,320 --> 00:27:54,600
Speaker 1: The increase in aerial density over time has followed a

465
00:27:54,640 --> 00:27:57,800
Speaker 1: path similar to what we see with semiconductors and with

466
00:27:57,880 --> 00:28:02,240
Speaker 1: Boar's law. To make all this possible, numerous discoveries and

467
00:28:02,280 --> 00:28:07,680
Speaker 1: advancements were acquired. Increasing aerial density meant not just shrinking

468
00:28:07,800 --> 00:28:11,560
Speaker 1: down components, but also expanding our understanding of stuff like

469
00:28:11,920 --> 00:28:16,040
Speaker 1: quantum effects and magnetism. It would take me an entire

470
00:28:16,320 --> 00:28:20,760
Speaker 1: series of podcasts to go through the various parts and

471
00:28:20,960 --> 00:28:24,119
Speaker 1: ideas and discoveries that all contributed to our ability to

472
00:28:24,200 --> 00:28:27,679
Speaker 1: store this much information on a hard disk drive. But

473
00:28:27,800 --> 00:28:31,600
Speaker 1: one bit I do want to mention specifically, just because

474
00:28:31,760 --> 00:28:36,159
Speaker 1: it's super cool. So you might know that one of

475
00:28:36,160 --> 00:28:38,920
Speaker 1: the challenges of keeping up with Moore's law has to

476
00:28:38,960 --> 00:28:43,440
Speaker 1: do with a quantum effect called tunneling. Well, in a

477
00:28:43,520 --> 00:28:48,720
Speaker 1: similar way, magnetic storage had its own physical limitation. Once

478
00:28:48,760 --> 00:28:52,600
Speaker 1: you try to squeeze the magnetic domains or regions into

479
00:28:52,640 --> 00:28:56,000
Speaker 1: smaller physical spaces, once you try to pack those zeros

480
00:28:56,040 --> 00:29:00,680
Speaker 1: and ones in even more tightly, you encountered something called

481
00:29:00,720 --> 00:29:05,240
Speaker 1: the super paramagnetic effect. Yeah, it's something that Mary Poppins

482
00:29:05,280 --> 00:29:09,720
Speaker 1: would pricing about. Super para magnetic anyway. The issue is

483
00:29:09,760 --> 00:29:12,680
Speaker 1: that when it's packed into such a small space, the

484
00:29:12,720 --> 00:29:17,800
Speaker 1: magnetization of individual domains could end up switching very easily,

485
00:29:17,840 --> 00:29:22,800
Speaker 1: particularly if there was any heat applied to the area.

486
00:29:22,920 --> 00:29:28,560
Speaker 1: So if your magnetization switches and your storage of information

487
00:29:28,640 --> 00:29:31,960
Speaker 1: is dependent upon magnetization, that would mean some of your

488
00:29:32,040 --> 00:29:34,600
Speaker 1: zeros would become ones, and some of your ones would

489
00:29:34,600 --> 00:29:39,080
Speaker 1: become zeros, so your files would become corrupted and unusable.

490
00:29:39,280 --> 00:29:44,240
Speaker 1: But the solution to this problem was actually pretty straightforward. See.

491
00:29:44,360 --> 00:29:48,400
Speaker 1: Up to that point, the magnetic direction of those little

492
00:29:48,480 --> 00:29:52,800
Speaker 1: domains had been longitudinal with regard to the platter. That

493
00:29:52,880 --> 00:29:57,400
Speaker 1: means the magnetic polls pointed along the same plane as

494
00:29:57,480 --> 00:30:00,680
Speaker 1: the platter, and scientists decided to change this so that

495
00:30:00,720 --> 00:30:04,600
Speaker 1: the magnetic fields were now perpendicular with respect to the platter.

496
00:30:04,960 --> 00:30:06,880
Speaker 1: So you can think of the magnetic fields is pointing

497
00:30:07,200 --> 00:30:10,600
Speaker 1: up and down from the platter surface, rather than say

498
00:30:10,840 --> 00:30:15,880
Speaker 1: forward or backward. This solved the superpara magnetic effect, and

499
00:30:15,880 --> 00:30:18,880
Speaker 1: it meant that engineers could increase the aerial density of

500
00:30:18,960 --> 00:30:22,280
Speaker 1: disks even further. Now, the fact that we're talking about

501
00:30:22,280 --> 00:30:25,680
Speaker 1: a mechanical process means that whenever you want to write

502
00:30:25,760 --> 00:30:29,160
Speaker 1: information to a disk, or you want to retrieve information

503
00:30:29,480 --> 00:30:32,880
Speaker 1: from a disk, that arm must move into place. The

504
00:30:33,000 --> 00:30:35,200
Speaker 1: disc has to spin up, the arm has to go

505
00:30:35,320 --> 00:30:38,320
Speaker 1: to each sector to pull up the relevant bits of

506
00:30:38,440 --> 00:30:41,080
Speaker 1: data that make up that file, and this takes a

507
00:30:41,120 --> 00:30:43,280
Speaker 1: little bit of time, and that explains part of the

508
00:30:43,320 --> 00:30:47,160
Speaker 1: delay to get information from storage into the computer's random

509
00:30:47,160 --> 00:30:50,480
Speaker 1: access memory where the CPU can make some use of it. Now,

510
00:30:50,480 --> 00:30:53,680
Speaker 1: it's not a huge amount of time. Typically, the seek time,

511
00:30:53,880 --> 00:30:57,640
Speaker 1: that is the delay between a CPU requesting a file

512
00:30:58,080 --> 00:31:00,680
Speaker 1: and when the first bite of data is sent from

513
00:31:00,680 --> 00:31:04,240
Speaker 1: storage to memory typically falls in the ten to twenty

514
00:31:04,320 --> 00:31:08,720
Speaker 1: millisecond range, so it's not like it's, you know, order

515
00:31:08,760 --> 00:31:10,880
Speaker 1: out for a pizza because you just decided to open

516
00:31:10,960 --> 00:31:15,000
Speaker 1: up a word document. However, the actual rate at which

517
00:31:15,080 --> 00:31:18,520
Speaker 1: a hard drive can deliver data to the CPU is

518
00:31:18,520 --> 00:31:21,880
Speaker 1: a different story. This is called the data rate, and

519
00:31:21,920 --> 00:31:24,560
Speaker 1: it tends to have a fairly wide range depending on

520
00:31:24,680 --> 00:31:28,760
Speaker 1: the hard drive, topping out at around two megabytes per second.

521
00:31:28,880 --> 00:31:31,360
Speaker 1: So if you're using a device with a hard drive

522
00:31:31,480 --> 00:31:35,080
Speaker 1: like this, you've probably experienced some delays as a CPU

523
00:31:35,160 --> 00:31:37,800
Speaker 1: requests data and then waits for it to be delivered.

524
00:31:38,160 --> 00:31:41,200
Speaker 1: The bigger and more complex the file, the longer the

525
00:31:41,200 --> 00:31:46,040
Speaker 1: weight tends to be, and because hard drives have moving components,

526
00:31:46,200 --> 00:31:49,240
Speaker 1: stuff can wear down over time. There are a few

527
00:31:49,280 --> 00:31:52,400
Speaker 1: potential points of failure, from the mechanical arm with the

528
00:31:52,440 --> 00:31:55,800
Speaker 1: transducers mounted on it, to the spinning motor that turns

529
00:31:55,840 --> 00:31:59,040
Speaker 1: the disks, to the alignment of the bladders themselves. If

530
00:31:59,080 --> 00:32:01,920
Speaker 1: you have a top that has a physical hard drive

531
00:32:01,920 --> 00:32:05,160
Speaker 1: in it and you were to accidentally drop that laptop

532
00:32:05,200 --> 00:32:07,680
Speaker 1: while it was working, there's a good chance that you

533
00:32:07,720 --> 00:32:11,400
Speaker 1: could dislodge those platters and then you've got a ruined

534
00:32:11,440 --> 00:32:15,360
Speaker 1: hard drive. Also, if any dust gets into that hard

535
00:32:15,400 --> 00:32:18,600
Speaker 1: disk drive, it can create read write errors or even

536
00:32:18,640 --> 00:32:21,000
Speaker 1: be enough to cause the arm to collide with the

537
00:32:21,040 --> 00:32:24,320
Speaker 1: hard disk and ruin everything. See these days, the read

538
00:32:24,360 --> 00:32:28,120
Speaker 1: write heads might just only be a few nanometers away

539
00:32:28,160 --> 00:32:30,320
Speaker 1: from the surface of the disk, so to us, if

540
00:32:30,360 --> 00:32:32,240
Speaker 1: we were to look at it, it would seem like

541
00:32:32,280 --> 00:32:35,080
Speaker 1: the two pieces are actually in contact with one another,

542
00:32:35,840 --> 00:32:38,560
Speaker 1: because that that space between them is so small that

543
00:32:38,600 --> 00:32:42,720
Speaker 1: even visible light is too big to show it. The

544
00:32:42,800 --> 00:32:45,800
Speaker 1: distance between them is about the distance of the width

545
00:32:45,840 --> 00:32:47,480
Speaker 1: of a couple of bands of d N and A.

546
00:32:47,720 --> 00:32:51,480
Speaker 1: It's tiny, so a single mote of dust would be

547
00:32:51,520 --> 00:32:55,360
Speaker 1: like a gargantuan boulder by comparison, and it's really hard

548
00:32:55,400 --> 00:32:57,960
Speaker 1: for me to get my mind wrapped around it, because

549
00:32:58,000 --> 00:33:01,560
Speaker 1: once we start talking about this level of scale, I

550
00:33:01,600 --> 00:33:05,960
Speaker 1: can kind of conceptualize it, but I can't visualize it now.

551
00:33:05,960 --> 00:33:08,800
Speaker 1: That's one of the reasons that these hard disks are

552
00:33:09,080 --> 00:33:12,240
Speaker 1: sealed in aluminum cases. It's to protect the platters from

553
00:33:12,520 --> 00:33:16,640
Speaker 1: dust and other contaminants. It's also why you should never

554
00:33:16,800 --> 00:33:19,680
Speaker 1: open up a hard disk drive unless you're okay with

555
00:33:19,720 --> 00:33:21,480
Speaker 1: the fact that it's never going to serve a useful

556
00:33:21,520 --> 00:33:25,040
Speaker 1: purpose outside of perhaps being an instruction to others on

557
00:33:25,520 --> 00:33:28,200
Speaker 1: how disk drives work or or showing people what it

558
00:33:28,240 --> 00:33:31,440
Speaker 1: looks like, because the chances are it's never going to

559
00:33:31,560 --> 00:33:35,320
Speaker 1: run again. This is also why stuff like clean rooms

560
00:33:35,520 --> 00:33:38,720
Speaker 1: need to exist. Clean rooms are facilities that use powerful

561
00:33:38,760 --> 00:33:42,680
Speaker 1: filtration and h VAC systems, along with incredibly strict protocols

562
00:33:43,000 --> 00:33:46,320
Speaker 1: to prevent the introduction of dust particles. Stuff like hard

563
00:33:46,440 --> 00:33:49,800
Speaker 1: drives and semiconductor chips need to be produced in clean

564
00:33:49,880 --> 00:33:52,520
Speaker 1: room facilities to avoid the possibility of even just one

565
00:33:53,040 --> 00:33:56,600
Speaker 1: moat of dust getting in there and ruining everything. Hard

566
00:33:56,600 --> 00:33:59,840
Speaker 1: disk drives tend to be fairly heavy and they require

567
00:33:59,880 --> 00:34:02,240
Speaker 1: a decent amount of power to operate, but they also

568
00:34:02,280 --> 00:34:05,360
Speaker 1: are cheap and they tend to be pretty high capacity.

569
00:34:05,880 --> 00:34:08,360
Speaker 1: Meaning we've advanced the science of designing hard drives to

570
00:34:08,360 --> 00:34:10,880
Speaker 1: a point where you can store an enormous amount of

571
00:34:10,920 --> 00:34:13,839
Speaker 1: information on a physical hard drive. But now it's time

572
00:34:13,880 --> 00:34:16,439
Speaker 1: for us to turn our attention to the alternative long

573
00:34:16,560 --> 00:34:20,200
Speaker 1: term storage solution, that of the solid state drive or

574
00:34:20,400 --> 00:34:22,920
Speaker 1: s s D. And when we come back, I'll tell

575
00:34:22,960 --> 00:34:25,480
Speaker 1: you all about it. But first let's take another quick

576
00:34:25,560 --> 00:34:36,520
Speaker 1: break with solid state drives. Were no longer talking about

577
00:34:36,640 --> 00:34:40,880
Speaker 1: mechanical systems. There are no moving parts. We're also no

578
00:34:40,920 --> 00:34:44,440
Speaker 1: longer talking about magnetic media, so we're not saving data

579
00:34:44,480 --> 00:34:48,319
Speaker 1: by magnetizing small areas on a chip or anything like that.

580
00:34:49,160 --> 00:34:52,160
Speaker 1: It's a form of nonvolatile memory, so the data does

581
00:34:52,239 --> 00:34:55,600
Speaker 1: stick around even if the computer or device is powered off.

582
00:34:56,160 --> 00:34:59,400
Speaker 1: The secret sauce in this case is that an s

583
00:34:59,400 --> 00:35:04,280
Speaker 1: s D follows into the storage medium of semiconductor chips.

584
00:35:05,120 --> 00:35:09,040
Speaker 1: Ss D chips share some similarities with other chips that

585
00:35:09,080 --> 00:35:11,600
Speaker 1: are on your computer. For example, remember when I was

586
00:35:11,640 --> 00:35:13,640
Speaker 1: talking about rom and Ram at the beginning of the

587
00:35:13,680 --> 00:35:16,920
Speaker 1: episode well. A ROM chip is a microchip that is

588
00:35:16,960 --> 00:35:20,920
Speaker 1: physically programmed to carry out specific sets of instructions, including

589
00:35:20,960 --> 00:35:24,759
Speaker 1: those necessary to boot up a computer. RAM chips are

590
00:35:24,800 --> 00:35:28,560
Speaker 1: microchips that can temporarily hold information for quick reference by

591
00:35:28,560 --> 00:35:31,799
Speaker 1: the CPU. The RAM and RAM chips are mounted on

592
00:35:31,840 --> 00:35:34,720
Speaker 1: the motherboard that's the main circuit board for a computer,

593
00:35:35,440 --> 00:35:40,120
Speaker 1: and SSD is not mounted on the motherboard like a

594
00:35:40,200 --> 00:35:43,520
Speaker 1: physical hard drive. It lives separate from the motherboard. It

595
00:35:43,560 --> 00:35:46,920
Speaker 1: connects to the motherboard via cables. In fact, if you

596
00:35:47,000 --> 00:35:50,600
Speaker 1: had a PC with a hard disk drive, you could

597
00:35:50,640 --> 00:35:53,520
Speaker 1: open up your computer, you could disconnect your hard disk

598
00:35:53,640 --> 00:35:56,960
Speaker 1: drive and you could install a solid state drive in

599
00:35:57,000 --> 00:36:00,000
Speaker 1: its place without really changing anything else in the computer

600
00:36:00,120 --> 00:36:03,879
Speaker 1: or The type of storage ss d s provide has

601
00:36:04,000 --> 00:36:08,319
Speaker 1: a somewhat confusing name. It's called flash memory. I say

602
00:36:08,360 --> 00:36:13,400
Speaker 1: it's confusing because we talked about random access memory or RAM.

603
00:36:13,400 --> 00:36:16,879
Speaker 1: But that stuff is volatile, right, It goes away when

604
00:36:16,920 --> 00:36:19,640
Speaker 1: you power the device down, that information is gone. But

605
00:36:19,680 --> 00:36:22,800
Speaker 1: flash memory and ss d s does not go away.

606
00:36:23,040 --> 00:36:26,320
Speaker 1: The data stays put. So we've got two different kinds

607
00:36:26,400 --> 00:36:29,799
Speaker 1: of memory here, one of which is actually storage. But

608
00:36:29,920 --> 00:36:33,040
Speaker 1: don't blame me because I don't come up with the names.

609
00:36:33,560 --> 00:36:36,680
Speaker 1: I'm just reporting them. Flash memory can come in a

610
00:36:36,719 --> 00:36:39,200
Speaker 1: couple of different varieties, and the type we find an

611
00:36:39,320 --> 00:36:43,520
Speaker 1: SSD drives is nan flash in A and D, but

612
00:36:43,600 --> 00:36:47,480
Speaker 1: there's also nor flash. So what the heck is up

613
00:36:47,520 --> 00:36:50,200
Speaker 1: with those names and how are these two things different? Well,

614
00:36:50,280 --> 00:36:53,040
Speaker 1: let's start with the names because they're based on a

615
00:36:53,280 --> 00:36:57,440
Speaker 1: very foundational component of computer science. It harkens back to

616
00:36:57,600 --> 00:37:02,759
Speaker 1: logic gates, which depend upon Boolean functions or Boolean algebra.

617
00:37:03,360 --> 00:37:07,040
Speaker 1: This is all about binary variables, so it's a variable

618
00:37:07,080 --> 00:37:11,239
Speaker 1: that can represent one of two values, like a zero

619
00:37:11,360 --> 00:37:15,400
Speaker 1: or a one. Logic gates are the practical implementation of

620
00:37:15,480 --> 00:37:20,000
Speaker 1: Boolean algebra. The gates determine what output is sent out

621
00:37:20,280 --> 00:37:23,920
Speaker 1: based on the incoming input. And let's use a simple

622
00:37:23,960 --> 00:37:29,600
Speaker 1: example with the and gate. The and gate accepts two

623
00:37:29,840 --> 00:37:33,160
Speaker 1: variables two variables as input, and the values for those

624
00:37:33,160 --> 00:37:36,560
Speaker 1: inputs can be either a zero or a one. The

625
00:37:36,640 --> 00:37:41,239
Speaker 1: and gate will output a one only if both inputs

626
00:37:41,320 --> 00:37:45,440
Speaker 1: are also ones. So if you feed two one bits

627
00:37:45,640 --> 00:37:48,640
Speaker 1: into the input of the hand gate, you get a

628
00:37:48,719 --> 00:37:51,320
Speaker 1: one bit as the output. But if you were to

629
00:37:51,400 --> 00:37:54,960
Speaker 1: feed in two zeros or a zero and a one,

630
00:37:55,200 --> 00:37:59,799
Speaker 1: or alternatively a one and a zero. We do differentiate

631
00:38:00,000 --> 00:38:04,040
Speaker 1: between these, then the end gate would produce a zero

632
00:38:04,080 --> 00:38:06,680
Speaker 1: as its output. So it's a set of rules. It says,

633
00:38:07,120 --> 00:38:09,440
Speaker 1: if I get two ones, I give you a one.

634
00:38:09,719 --> 00:38:11,960
Speaker 1: If I get anything else, I give you a zero.

635
00:38:12,560 --> 00:38:17,080
Speaker 1: By contrast, and or gate produces a one, also known

636
00:38:17,120 --> 00:38:20,880
Speaker 1: as a high output if at least one input is

637
00:38:20,960 --> 00:38:23,839
Speaker 1: also a one. So the or gate will send out

638
00:38:23,840 --> 00:38:26,880
Speaker 1: a one if the inputs are one in zero, zero

639
00:38:26,960 --> 00:38:30,200
Speaker 1: and one or one in one, and it only produces

640
00:38:30,239 --> 00:38:34,279
Speaker 1: a zero if the inputs are both zero. So this case,

641
00:38:34,400 --> 00:38:36,120
Speaker 1: you give me two zeros, I give you a zero.

642
00:38:36,360 --> 00:38:38,799
Speaker 1: You give me any other combination, I give you a one.

643
00:38:39,440 --> 00:38:43,239
Speaker 1: Logic gates are a way to build out complex responses

644
00:38:43,280 --> 00:38:46,800
Speaker 1: to inputs. They are the instructions that tell the computer

645
00:38:47,080 --> 00:38:51,640
Speaker 1: what outcome to produce given a specific input. So let's

646
00:38:51,680 --> 00:38:55,680
Speaker 1: talk specifically about nand and nor. These are sort of

647
00:38:55,719 --> 00:39:00,440
Speaker 1: the bizarro versions of the and A or gates. A

648
00:39:00,600 --> 00:39:04,360
Speaker 1: nand gate produces a one output with every pair of

649
00:39:04,400 --> 00:39:08,040
Speaker 1: inputs except for one one. So in other words, if

650
00:39:08,080 --> 00:39:11,120
Speaker 1: you give me a zero, zero, a zero one, or

651
00:39:11,200 --> 00:39:14,560
Speaker 1: a one zero, I will give you a one output.

652
00:39:15,160 --> 00:39:17,239
Speaker 1: If you were to give me one one, I would

653
00:39:17,239 --> 00:39:21,040
Speaker 1: give you a zero output. A nore gate will only

654
00:39:21,120 --> 00:39:24,840
Speaker 1: produce a one output if both inputs are zero. So

655
00:39:24,880 --> 00:39:27,120
Speaker 1: you give me a zero one, a one zero, or

656
00:39:27,160 --> 00:39:29,400
Speaker 1: a one one. I give you a big fat zero.

657
00:39:29,880 --> 00:39:32,560
Speaker 1: You give me a zero zero. Hey, it's your lucky day.

658
00:39:32,560 --> 00:39:35,000
Speaker 1: I give you a one. Now. I've done an episode

659
00:39:35,000 --> 00:39:38,439
Speaker 1: on logic gates many years ago to explain how why

660
00:39:38,480 --> 00:39:41,440
Speaker 1: these are important, how they work in the realm of

661
00:39:41,520 --> 00:39:45,120
Speaker 1: computer science, and what this actually all means, and it

662
00:39:45,200 --> 00:39:47,080
Speaker 1: may be time for me to revisit that and to

663
00:39:47,160 --> 00:39:49,120
Speaker 1: kind of give it a deeper treatment, because it really

664
00:39:49,120 --> 00:39:51,960
Speaker 1: gives you an appreciation of the logical design that you

665
00:39:52,040 --> 00:39:54,920
Speaker 1: have to create so that computers will do the stuff

666
00:39:54,960 --> 00:39:58,640
Speaker 1: you want them to do. But for now, let's just

667
00:39:59,200 --> 00:40:02,239
Speaker 1: put that aside and go back to nand versus NOR

668
00:40:02,480 --> 00:40:06,520
Speaker 1: flash memory. With both nand and NOR flash memory cards,

669
00:40:06,840 --> 00:40:10,799
Speaker 1: you have transistors arranged in cells. They're laid out in

670
00:40:11,120 --> 00:40:14,360
Speaker 1: a grid format, so you've got rows and you've got

671
00:40:14,400 --> 00:40:18,920
Speaker 1: columns of transistors. In NOR flash cells, the grids are

672
00:40:19,000 --> 00:40:21,480
Speaker 1: wired in parallel to one another, so you can think

673
00:40:21,520 --> 00:40:25,120
Speaker 1: of them as being wired side by side. In nand

674
00:40:25,320 --> 00:40:29,279
Speaker 1: flash cells. They're wired in series, which means you go

675
00:40:29,400 --> 00:40:32,400
Speaker 1: from one to the next one and you wire them

676
00:40:32,480 --> 00:40:36,600
Speaker 1: all in order in a sequence. NAND cells have a

677
00:40:36,680 --> 00:40:40,280
Speaker 1: greater density of transistors and they also use fewer wires

678
00:40:40,320 --> 00:40:43,480
Speaker 1: than NOR cells. They can read and write data faster

679
00:40:43,560 --> 00:40:46,520
Speaker 1: than NOR flash memory, so nand flash is great for

680
00:40:46,600 --> 00:40:50,080
Speaker 1: the solid state drive, whereas NOR flash tends to be

681
00:40:50,200 --> 00:40:52,920
Speaker 1: used for read only purposes, kind of like the wrong

682
00:40:53,120 --> 00:40:56,319
Speaker 1: chips on a motherboard. If you were to put an

683
00:40:56,480 --> 00:40:59,560
Speaker 1: SSD and a hard disk drive mint for the exact

684
00:40:59,640 --> 00:41:02,799
Speaker 1: same drive bay in a computer case next to each other,

685
00:41:03,040 --> 00:41:04,600
Speaker 1: like if you were to take out a hard disk

686
00:41:04,680 --> 00:41:07,560
Speaker 1: drive at an SSD drive and you put them side

687
00:41:07,560 --> 00:41:09,840
Speaker 1: by side, they would look fairly similar there both be

688
00:41:10,160 --> 00:41:13,160
Speaker 1: and metal you know, aluminum cases, and they would be

689
00:41:13,200 --> 00:41:16,680
Speaker 1: the same size. But the SSD would have no mechanical

690
00:41:16,719 --> 00:41:19,640
Speaker 1: parts and it would likely have a good amount of

691
00:41:19,760 --> 00:41:24,080
Speaker 1: unused space inside the case. The reason for that is

692
00:41:24,120 --> 00:41:27,160
Speaker 1: for a convenience, the solid state drive needs to match

693
00:41:27,200 --> 00:41:30,240
Speaker 1: the physical shape and size of the hard disk drive

694
00:41:30,640 --> 00:41:33,240
Speaker 1: so that it can fit into the computer case properly,

695
00:41:33,719 --> 00:41:37,399
Speaker 1: so it's really just there so it'll it'll be able

696
00:41:37,440 --> 00:41:41,279
Speaker 1: to fit the model of the computer case, it's not

697
00:41:41,920 --> 00:41:45,400
Speaker 1: necessary for the ss D to actually function. The nand

698
00:41:45,520 --> 00:41:50,040
Speaker 1: semiconductor chips in an ss D have transistors arranged in

699
00:41:50,080 --> 00:41:53,160
Speaker 1: a grid, which means that the grid has columns and rows,

700
00:41:53,200 --> 00:41:56,800
Speaker 1: and a chain of transistors conducting a current would represent

701
00:41:56,880 --> 00:42:00,239
Speaker 1: the value of one. A chain that is not conducting

702
00:42:00,280 --> 00:42:04,120
Speaker 1: current represents a zero. And at first, before you've stored

703
00:42:04,320 --> 00:42:07,520
Speaker 1: any data on a solid state drive, you haven't. You

704
00:42:07,560 --> 00:42:11,279
Speaker 1: haven't saved anything to it. All the transistors would be

705
00:42:11,320 --> 00:42:14,239
Speaker 1: carrying currents, so they would all be set to one.

706
00:42:14,800 --> 00:42:17,919
Speaker 1: Saving data to the drive means that the solid state

707
00:42:18,000 --> 00:42:21,800
Speaker 1: drive will actually start to block current to specific transistors

708
00:42:22,120 --> 00:42:25,600
Speaker 1: to switch them from a one to a zero. Now,

709
00:42:25,600 --> 00:42:28,920
Speaker 1: at each intersection of this column and row, you get

710
00:42:28,960 --> 00:42:32,480
Speaker 1: a pair of transistors that form a cell. One of

711
00:42:32,520 --> 00:42:35,399
Speaker 1: the two transistors is a control gate and the other

712
00:42:35,640 --> 00:42:38,640
Speaker 1: is a floating gate. To quote the house Stuff Works

713
00:42:38,719 --> 00:42:42,560
Speaker 1: article on it quote, when current reaches the control gate,

714
00:42:42,840 --> 00:42:47,120
Speaker 1: electrons flow onto the floating gate, creating a net positive

715
00:42:47,200 --> 00:42:51,799
Speaker 1: charge that interrupts current flow. By applying precise voltages to

716
00:42:51,840 --> 00:42:56,000
Speaker 1: the transistors, a unique pattern of ones and zeros emerges.

717
00:42:56,239 --> 00:42:59,120
Speaker 1: End quote that article. By the way, was written by

718
00:42:59,120 --> 00:43:03,000
Speaker 1: William Harris, not written by me. It's a great article.

719
00:43:03,280 --> 00:43:06,560
Speaker 1: I highly recommend reading How solid state Drives Work if

720
00:43:06,600 --> 00:43:10,440
Speaker 1: you want to learn more. One big advantage of solid

721
00:43:10,440 --> 00:43:14,160
Speaker 1: state drives over hard drives is that with no moving parts,

722
00:43:14,440 --> 00:43:17,279
Speaker 1: the computer can access data from any part of the

723
00:43:17,320 --> 00:43:20,680
Speaker 1: solid state drive with the same speed as any other part.

724
00:43:20,960 --> 00:43:23,719
Speaker 1: There's no arm that needs to move into position, there's

725
00:43:23,760 --> 00:43:26,320
Speaker 1: no platter that needs to spend, and this means that

726
00:43:26,400 --> 00:43:29,520
Speaker 1: data can move from storage to RAM or into cash

727
00:43:29,600 --> 00:43:32,879
Speaker 1: memory much faster than it would with a hard disk drive,

728
00:43:33,520 --> 00:43:36,960
Speaker 1: and it's fast enough to make a noticeable difference. And

729
00:43:37,000 --> 00:43:40,000
Speaker 1: they also use less power than hard disk drives do,

730
00:43:40,160 --> 00:43:43,160
Speaker 1: so that's another bonus. Now, a few years ago, there

731
00:43:43,160 --> 00:43:46,279
Speaker 1: were some pretty big differences in storage capacity between hard

732
00:43:46,360 --> 00:43:49,719
Speaker 1: drives and solid state drives. For a while, the hard

733
00:43:49,840 --> 00:43:53,640
Speaker 1: drive had a really good head start, and so for

734
00:43:53,680 --> 00:43:56,440
Speaker 1: a few years if you wanted a lot of storage,

735
00:43:56,800 --> 00:43:58,800
Speaker 1: really the hard drive was the way to go. You

736
00:43:58,840 --> 00:44:01,040
Speaker 1: can get much higher copa a city hard drives. But

737
00:44:01,120 --> 00:44:04,160
Speaker 1: today solid state drives are really caught up and it's

738
00:44:04,160 --> 00:44:06,799
Speaker 1: possible to buy a solid state drive with the same

739
00:44:06,840 --> 00:44:11,080
Speaker 1: storage capacity as a high capacity hard disk. Drive. However,

740
00:44:11,560 --> 00:44:15,400
Speaker 1: solid state drives are much more expensive now. The cost

741
00:44:15,520 --> 00:44:20,080
Speaker 1: fluctuates based on numerous market factors, but you're likely to

742
00:44:20,120 --> 00:44:23,520
Speaker 1: spend double or more than what it would cost to

743
00:44:23,560 --> 00:44:25,799
Speaker 1: get a hard disk drive that has the exact same

744
00:44:25,840 --> 00:44:30,720
Speaker 1: storage capacity, so they are much more expensive. Interestingly, solid

745
00:44:30,760 --> 00:44:33,920
Speaker 1: state drives actually do wear out over time, despite the

746
00:44:33,920 --> 00:44:37,040
Speaker 1: fact that they don't have moving parts. So the application

747
00:44:37,080 --> 00:44:40,440
Speaker 1: of voltages on transistors, you know, changing the charge of

748
00:44:40,440 --> 00:44:45,240
Speaker 1: those transistors that slowly wears out the transistors, and after

749
00:44:45,360 --> 00:44:48,839
Speaker 1: a number of cycles a cycle being going from say

750
00:44:49,160 --> 00:44:52,839
Speaker 1: a one to a zero back to a one. After

751
00:44:52,920 --> 00:44:55,440
Speaker 1: a certain number of those, the cells will start to

752
00:44:55,480 --> 00:44:59,520
Speaker 1: wear out. Now, the typical number of cycles ranges in

753
00:44:59,560 --> 00:45:02,759
Speaker 1: the thoul posens of cycles, and computers are really good

754
00:45:02,760 --> 00:45:06,560
Speaker 1: at using up available storage space that hasn't been through

755
00:45:06,760 --> 00:45:10,080
Speaker 1: a lot of cycles already, so typically you don't have

756
00:45:10,120 --> 00:45:12,440
Speaker 1: to worry about the solid state drive giving out before

757
00:45:12,560 --> 00:45:15,160
Speaker 1: some other component on your machine gives out. So in

758
00:45:15,200 --> 00:45:17,920
Speaker 1: other words, you're far more likely to need to upgrade

759
00:45:17,960 --> 00:45:21,799
Speaker 1: your computer due to your processor or something else other

760
00:45:21,920 --> 00:45:24,920
Speaker 1: than the solid state drive. It would be unusual for

761
00:45:24,960 --> 00:45:28,120
Speaker 1: you to use a solid state drive so long that

762
00:45:28,120 --> 00:45:31,920
Speaker 1: that cycle thing becomes a real issue. One interesting thing

763
00:45:31,960 --> 00:45:34,680
Speaker 1: to remember is that there's always going to be bottlenecks

764
00:45:34,719 --> 00:45:38,640
Speaker 1: for data transfer. You might speed up in one area,

765
00:45:38,760 --> 00:45:41,560
Speaker 1: but you will start to find restrictions in other areas.

766
00:45:41,960 --> 00:45:44,520
Speaker 1: The limitation might be in the amount of RAM you

767
00:45:44,600 --> 00:45:46,719
Speaker 1: have in your machine. The RAMS capacity is going to

768
00:45:46,840 --> 00:45:49,640
Speaker 1: limit how much can be loaded into memory, which is

769
00:45:49,640 --> 00:45:51,960
Speaker 1: why a lot of folks advocate for adding more RAM

770
00:45:52,040 --> 00:45:54,640
Speaker 1: to a machine if you want to make it go faster.

771
00:45:55,040 --> 00:45:57,680
Speaker 1: Of course, this only works if the machine actually has

772
00:45:57,719 --> 00:46:01,400
Speaker 1: the capability to accept more RAM. You might have a

773
00:46:01,440 --> 00:46:04,000
Speaker 1: device where you can't upgrade the RAM, or you might

774
00:46:04,000 --> 00:46:05,920
Speaker 1: have a device where you've got as much RAM in

775
00:46:06,000 --> 00:46:09,680
Speaker 1: it as the motherboard can support. But then there's also

776
00:46:10,080 --> 00:46:13,040
Speaker 1: the bus, and a bus in a computer is a

777
00:46:13,040 --> 00:46:17,600
Speaker 1: connection between different components within the computer itself. Can actually

778
00:46:17,640 --> 00:46:20,720
Speaker 1: also be external components that are attached to the computer.

779
00:46:21,120 --> 00:46:23,640
Speaker 1: Bus is a very generic term, but you can think

780
00:46:23,640 --> 00:46:28,560
Speaker 1: of the bus as a highway between two different components,

781
00:46:28,600 --> 00:46:31,640
Speaker 1: and data travels down this highway to get from one

782
00:46:31,680 --> 00:46:35,520
Speaker 1: to the other. So like the memory to the CPU,

783
00:46:35,600 --> 00:46:38,560
Speaker 1: and a lot of devices placed the memory physically close

784
00:46:38,640 --> 00:46:42,520
Speaker 1: to the CPU to improve data transfer efficiency. It's kind

785
00:46:42,520 --> 00:46:44,640
Speaker 1: of blows my mind to think about that, that the

786
00:46:44,680 --> 00:46:48,440
Speaker 1: difference between you know, a centimeter can make a big

787
00:46:48,480 --> 00:46:53,480
Speaker 1: difference in and transfer efficiency, and it's it's kind of crazy,

788
00:46:53,520 --> 00:46:57,200
Speaker 1: but like a highway, a bus has a capacity limit

789
00:46:57,239 --> 00:46:59,840
Speaker 1: to how much data can actually cross it in a

790
00:47:00,040 --> 00:47:02,680
Speaker 1: of an instant, a bus will have a limit on

791
00:47:02,719 --> 00:47:06,239
Speaker 1: how many bits per second can move across it. So

792
00:47:06,280 --> 00:47:09,600
Speaker 1: if you're trying to build a fast PC, you've got

793
00:47:09,600 --> 00:47:12,640
Speaker 1: to take a lot of different things into consideration, including

794
00:47:12,880 --> 00:47:16,560
Speaker 1: the processors, which might include not just a central processing unit,

795
00:47:16,640 --> 00:47:20,919
Speaker 1: but maybe one or more graphics processing units, the RAM

796
00:47:20,960 --> 00:47:25,160
Speaker 1: that supports those processors, the storage system you're going to

797
00:47:25,239 --> 00:47:29,680
Speaker 1: be using, and more so making your computer go faster.

798
00:47:30,280 --> 00:47:32,160
Speaker 1: There are a lot of different approaches you can take.

799
00:47:32,640 --> 00:47:35,840
Speaker 1: Adding more rams usually a pretty good one, but switching

800
00:47:35,880 --> 00:47:38,000
Speaker 1: to a different kind of storage if you're using a

801
00:47:38,000 --> 00:47:41,120
Speaker 1: hard disk drive, if you switch to a solid state drive,

802
00:47:41,840 --> 00:47:44,719
Speaker 1: that can really help out a lot. It's also generally

803
00:47:44,760 --> 00:47:48,840
Speaker 1: more reliable than a hard disk drive. Fewer failures happen

804
00:47:48,920 --> 00:47:53,640
Speaker 1: with them. In general, they're always exceptions, and it's always, always,

805
00:47:53,680 --> 00:47:57,839
Speaker 1: always a good idea to back up your data. Back

806
00:47:57,880 --> 00:48:00,000
Speaker 1: it up, on an external drive or back it up

807
00:48:00,000 --> 00:48:03,480
Speaker 1: on a cloud service. Back it up somewhere just in

808
00:48:03,560 --> 00:48:06,520
Speaker 1: case one of those catastrophic failures does happen, you'll still

809
00:48:06,520 --> 00:48:10,359
Speaker 1: be able to get to the important information. So I

810
00:48:10,440 --> 00:48:13,760
Speaker 1: hope that all of this was useful. It's really interesting stuff.

811
00:48:13,800 --> 00:48:15,880
Speaker 1: Like I said, we can do a full episode on

812
00:48:15,920 --> 00:48:19,160
Speaker 1: things like logic Gates further down the road. Logic is

813
00:48:19,160 --> 00:48:21,920
Speaker 1: one of those things I really enjoy because it's all

814
00:48:21,960 --> 00:48:26,000
Speaker 1: about just learning basic rules, and those rules are solid,

815
00:48:26,640 --> 00:48:29,680
Speaker 1: Like the only thing that changes is what you're feeding

816
00:48:29,800 --> 00:48:33,960
Speaker 1: into those rules. But the rules themselves are dependable. And

817
00:48:34,000 --> 00:48:36,680
Speaker 1: in the world I live in now, when I find

818
00:48:36,719 --> 00:48:43,440
Speaker 1: something that's dependable, I hug it, I hug logic Gates. Guys. Okay,

819
00:48:43,440 --> 00:48:46,000
Speaker 1: well that was weird. If you have any suggestions for

820
00:48:46,120 --> 00:48:49,840
Speaker 1: future episodes of tech Stuff, whether it's a technology, a

821
00:48:49,920 --> 00:48:53,000
Speaker 1: trend in tech, a person in tech, a company, anything

822
00:48:53,040 --> 00:48:55,799
Speaker 1: like that, reach out to me. You can get in

823
00:48:55,840 --> 00:48:58,200
Speaker 1: touch over on Twitter. The handle for the show is

824
00:48:58,280 --> 00:49:01,800
Speaker 1: tech Stuff HSB you and I'll talk to you again

825
00:49:02,680 --> 00:49:11,000
Speaker 1: really soon. Y. Text Stuff is an I Heart Radio production.

826
00:49:11,239 --> 00:49:14,040
Speaker 1: For more podcasts from I Heart Radio, visit the I

827
00:49:14,160 --> 00:49:17,400
Speaker 1: Heart Radio app Apple podcasts, or wherever you listen to

828
00:49:17,440 --> 00:49:18,360
Speaker 1: your favorite shows.