WEBVTT - TechStuff Looks at Solid State Drives 0:00:00.280 --> 0:00:02.920 Brought to you by the reinvented two thousand twelve Camray. 0:00:03.160 --> 0:00:08.880 It's ready. Are you get in touch with technology with 0:00:08.960 --> 0:00:17.560 tech Stuff from how stuff works dot com. Hello everyone, 0:00:17.760 --> 0:00:20.440 and welcome to tech stuff. My name is Chris Poulette 0:00:20.440 --> 0:00:23.439 and I am an editor how stuff works dot com. 0:00:23.560 --> 0:00:27.280 The guy sitting across from me, he is Jonathan STRICKLANDUS 0:00:27.480 --> 0:00:30.520 senior writer at how stuff works dot com. Hey there, 0:00:31.840 --> 0:00:34.560 So today we wanted to talk a little bit about 0:00:34.960 --> 0:00:40.000 solid state drives and what makes them work and how 0:00:40.040 --> 0:00:44.160 they are different from the traditional forms of storage media 0:00:44.280 --> 0:00:47.480 that we are used to in the world of computers. Now, 0:00:47.720 --> 0:00:49.479 some of you out there may be used to solid 0:00:49.479 --> 0:00:51.480 state drives, and so you're thinking how our solid state 0:00:51.560 --> 0:00:53.640 drives different from other solid state drives. That's not what 0:00:53.680 --> 0:00:55.920 I mean. I mean those of us who have used 0:00:56.760 --> 0:01:01.320 hard disks that use magnetic storage in some form, and uh, 0:01:01.360 --> 0:01:05.320 there are a lot of differences, mainly mechanical physical differences, 0:01:05.360 --> 0:01:08.080 because when you're talking about a hard disk, I guess 0:01:08.480 --> 0:01:12.080 a traditional hard hard disk drive, you're talking about a 0:01:12.120 --> 0:01:16.920 device that has moving parts and um it has platters 0:01:16.920 --> 0:01:21.040 that are that have information stored on the magnetically use 0:01:21.120 --> 0:01:25.120 magnetic fields to change uh, informations into zeros and ones, 0:01:25.560 --> 0:01:28.520 those bits that we use to create the data that 0:01:28.560 --> 0:01:33.520 computers can understand. And you have a physical device that 0:01:33.640 --> 0:01:36.280 reads that information off of the platters the players have 0:01:36.319 --> 0:01:39.960 to spin for this to happen. Uh. Turns out those 0:01:40.000 --> 0:01:43.440 devices they take up, they take a lot of time 0:01:43.840 --> 0:01:47.840 to pull that information up. Relatively speaking. When I say 0:01:47.840 --> 0:01:51.840 a lot of time, we're talking milliseconds. But still, yeah, 0:01:51.840 --> 0:01:56.160 there are when you think about getting information into and 0:01:56.320 --> 0:02:00.760 out of uh your computers, basically what you're doing right now. 0:02:00.840 --> 0:02:04.760 There there are several different ways it does that. There's uh, 0:02:04.880 --> 0:02:10.600 some information that is available for you know, ready retrieval. Um. 0:02:10.639 --> 0:02:13.000 You know, in the cash that's built in you have 0:02:13.120 --> 0:02:16.120 level one level two cash. You may not have necessarily 0:02:16.160 --> 0:02:19.360 known what that was. I didn't uh you know, and 0:02:20.280 --> 0:02:22.760 it's sort of uh, it's sort of intuitive when you 0:02:22.760 --> 0:02:25.160 think about it. It keeps it this information in this 0:02:25.280 --> 0:02:30.200 cash on hand, so stuff that you're doing right now 0:02:30.760 --> 0:02:33.720 is kept right there close by in a very fast 0:02:34.320 --> 0:02:38.080 um uh in a very fast retrieval system so that 0:02:38.120 --> 0:02:41.280 I can pull it back at at at a nanoseconds. Notice, 0:02:41.560 --> 0:02:44.000 right in fact, if we if we go. It's easy 0:02:44.040 --> 0:02:47.040 to imagine this if we think of the CPU first. 0:02:47.360 --> 0:02:49.600 Just look at the central processing US of your computer 0:02:49.720 --> 0:02:51.760 and think of that as this is the place where 0:02:52.440 --> 0:02:56.760 operations are executed upon data. Right. Yeah, it pulls data in, 0:02:57.040 --> 0:02:59.440 it executes an operation on it, it gets a result. 0:02:59.560 --> 0:03:03.520 That's the purpose of the CPU. Now, CPU has something 0:03:03.560 --> 0:03:07.919 called registers. Registers are where the CPU can hold data. 0:03:08.040 --> 0:03:12.400 But registers hold a very small amount of data comparatively speaking, 0:03:13.120 --> 0:03:16.720 usually just a few hundred bytes. You can build larger registers, 0:03:16.720 --> 0:03:19.400 and you can build more registers for your CPU, but 0:03:19.480 --> 0:03:22.240 that tends to be pretty expensive. Now, the benefit of 0:03:22.280 --> 0:03:25.760 having information and registers on the CPU is that you 0:03:25.840 --> 0:03:29.600 have next to no time at all between when you 0:03:29.639 --> 0:03:32.480 pull the information and when you can execute an operation 0:03:32.560 --> 0:03:36.400 upon that information. So that means that we say that 0:03:36.480 --> 0:03:41.880 the latency for the information within a CPUs registers is zero. 0:03:42.320 --> 0:03:45.400 Latency is that time between when you retrieve information and 0:03:45.440 --> 0:03:47.560 when you can or when you send a request for 0:03:47.680 --> 0:03:50.400 information and when you actually retrieve it. Yes, so there's 0:03:50.440 --> 0:03:55.000 no latency when you're talking about a the CPUs registers. However, 0:03:55.440 --> 0:03:58.840 only a few hundred bytes are exist within those registers. 0:03:58.840 --> 0:04:01.240 It's not a lot of data. Now you were talking 0:04:01.240 --> 0:04:03.640 about the cash is the level one cash is kind 0:04:03.640 --> 0:04:07.320 of the information that the CPU uses frequently. It's going 0:04:07.360 --> 0:04:09.560 to in whatever application you have to be in at 0:04:09.600 --> 0:04:12.120 that time, right, So this is information that the CPU 0:04:12.200 --> 0:04:14.640 is having to go to again and again, and it 0:04:14.680 --> 0:04:17.360 needs it to be as close as possible so that 0:04:17.800 --> 0:04:21.039 it keeps that latency down because of course, if you 0:04:21.080 --> 0:04:23.440 have to go further out for your information, it's going 0:04:23.480 --> 0:04:25.680 to take longer for it to get back. So at 0:04:25.760 --> 0:04:30.279 level one cash, you're talking about around bytes of data 0:04:30.440 --> 0:04:36.839 per CPU core if you're running an ivy Bridge processor 0:04:36.880 --> 0:04:40.600 and I seven core ivy Bridge processor from Mentel, so 0:04:40.640 --> 0:04:46.480 that's thirty bytes per uh core and as far as 0:04:46.520 --> 0:04:50.120 that level one cash goes and that takes a nanosecond 0:04:50.320 --> 0:04:53.720 to pull that data up, So that's one billionth of 0:04:53.720 --> 0:04:57.520 a second. Yep, and uh you know, just on the 0:04:57.680 --> 0:05:00.839 just to comment on the ivy Bridge note, the cash 0:05:00.920 --> 0:05:04.960 is themselves, um you know they exist on all these 0:05:04.960 --> 0:05:09.880 different processors. That's just that figure just specific to the 0:05:09.920 --> 0:05:13.120 ivy Bridge, but other processors do have this as well. Yes, 0:05:13.200 --> 0:05:15.520 just in case there was any confusion, and and then 0:05:15.560 --> 0:05:17.800 you could have a level to cash, which is slightly 0:05:17.800 --> 0:05:19.760 further out, you know, think of think of it like 0:05:19.920 --> 0:05:23.320 concentric circles, right, So the level two cash is a 0:05:23.320 --> 0:05:26.560 concentric circle further out from the CPU. It can hold 0:05:26.560 --> 0:05:28.839 a little more data. It's a little slower to pull 0:05:28.839 --> 0:05:31.599 that information up, it's a few nano seconds. Then it 0:05:31.680 --> 0:05:34.479 may even have a level three cash. Not all CPUs do, 0:05:35.120 --> 0:05:38.359 but many do. And then that is even larger and 0:05:38.400 --> 0:05:42.159 holds even more data and takes even longer again in 0:05:42.240 --> 0:05:45.200 relative terms, to get that data to the CPU. And 0:05:45.240 --> 0:05:50.039 beyond that, that's when you go to your computer's actual memory, 0:05:50.400 --> 0:05:52.400 because all the stuff we've been talking about right now 0:05:52.760 --> 0:05:56.800 is all located on the CPU die itself. So it's 0:05:56.839 --> 0:06:00.440 all part of that that chip. Yeah, it's not you know, 0:06:00.480 --> 0:06:03.400 it's not separate. It's on another element that's on the motherboard. 0:06:03.440 --> 0:06:05.719 This is all part of the CPU. Yeah. If you 0:06:05.800 --> 0:06:07.599 if you pull your hard drive out of the computer 0:06:07.920 --> 0:06:10.840 toss it on the floor, don't don't do that. Um. 0:06:10.880 --> 0:06:13.960 And uh, and you you pull the RAM chips out 0:06:14.000 --> 0:06:15.800 of your computer and toss them on the floor, don't 0:06:15.800 --> 0:06:18.919 do that either. Um. Then I'm glad you did that 0:06:18.960 --> 0:06:21.599 because I was thinking it it was just funny that 0:06:21.640 --> 0:06:25.880 you said it. Um, then the uh, the registry and 0:06:25.880 --> 0:06:29.280 the cashes will still be there on the computer and 0:06:29.360 --> 0:06:31.280 I won't be able to do a whole lot with them. 0:06:31.279 --> 0:06:35.600 But still, um, so you know that, just to illustrate that. 0:06:35.920 --> 0:06:38.839 So yes, the next part we'll we'll pick this stuff 0:06:39.000 --> 0:06:41.000 gently back up off the floor and put it inside 0:06:41.240 --> 0:06:45.360 the RAM is essentially the next ring out if you will, 0:06:45.400 --> 0:06:47.920 from the cashes. However, many that you happen to have 0:06:47.960 --> 0:06:51.080 on your CPU, right, and these these memory chips have 0:06:51.360 --> 0:06:55.840 been optimized so that the latency is really really low. However, 0:06:56.600 --> 0:07:00.960 they are not located on the CPU. No, they are 0:07:01.000 --> 0:07:05.960 connected by circuits by by pathways to the CPU. Well, 0:07:06.080 --> 0:07:08.719 because they are not located on the CPU, and because 0:07:08.760 --> 0:07:11.760 that information does have to actually travel a physical distance, 0:07:12.240 --> 0:07:16.480 that increases the latency time. So when your CPU has 0:07:16.520 --> 0:07:19.800 to pull information out and that information is not in 0:07:19.840 --> 0:07:22.320 the cash for the CPU, it has to but it 0:07:22.400 --> 0:07:26.360 resides within the memory of your computer, then it has 0:07:26.400 --> 0:07:30.640 to travel this pathway and for the the request and retrieval, 0:07:30.680 --> 0:07:33.560 that can take between forty and eighty nanoseconds. So we're 0:07:33.560 --> 0:07:36.840 still talking a fraction of a second. Yeah, I mean 0:07:36.840 --> 0:07:39.560 this is These are are times that you or I 0:07:39.640 --> 0:07:41.960 will not even be able to notice. Yeah, we can't. 0:07:42.240 --> 0:07:47.119 We we have no ability to to register that using 0:07:47.200 --> 0:07:52.200 our senses. We would have to use incredibly sensitive measurement 0:07:52.840 --> 0:07:55.040 devices in order to be able to tell the difference 0:07:55.040 --> 0:07:59.040 between forty and eighty nanoseconds. To us, there's no meaningful 0:07:59.400 --> 0:08:03.280 difference at But the uh. But the thing about RAM 0:08:03.440 --> 0:08:07.240 is when you shut off the computer, all that information 0:08:07.240 --> 0:08:12.400 that's in RAM disappears. Yeah, it's it's held there by 0:08:12.440 --> 0:08:16.200 the electrical charge UM, which is relative to the computer. 0:08:16.280 --> 0:08:19.440 Now you're hard drive with the information stored we're talking 0:08:19.480 --> 0:08:23.760 traditional with the information stored manet magnetically on those platters. UM, 0:08:23.800 --> 0:08:25.640 it's able to save that stuff so that when you 0:08:25.680 --> 0:08:28.160 turn the computer back on, you can read the hard 0:08:28.200 --> 0:08:30.800 drive and get it back. UM. The thing is that 0:08:32.640 --> 0:08:36.800 hard drives have different rotating speeds UM. Typical to see 0:08:36.800 --> 0:08:42.160 a laptop with a rpm uh drive or or even 0:08:43.840 --> 0:08:46.320 revolutions per minute just in case you aren't familiar with 0:08:46.320 --> 0:08:48.720 the term UM, and you're more likely to see fat 0:08:48.800 --> 0:08:52.920 those and faster in desktop computers. UM. And the faster 0:08:53.120 --> 0:08:56.960 these rotate in general, that means the faster the information 0:08:57.000 --> 0:08:59.800 can be pulled from the hard drive and sent to 0:09:00.440 --> 0:09:04.720 memory and then onto your CPU. UM. So if you 0:09:04.880 --> 0:09:07.320 if you took your hard drive, the thing is that 0:09:07.559 --> 0:09:11.920 these systems are are delicate their their machine to very 0:09:11.960 --> 0:09:16.000 precise tolerances. That the head um that reads the disk, 0:09:16.120 --> 0:09:18.440 it looks like it looks like a record player for 0:09:18.440 --> 0:09:20.800 those of us who remember that, but the the head 0:09:20.840 --> 0:09:24.000 doesn't actually touch the disc. If it does, that's what 0:09:24.040 --> 0:09:26.960 they call a bad thing. Yeah, it looks like it's 0:09:27.040 --> 0:09:29.640 in contact because it's so close to the platter, but 0:09:29.679 --> 0:09:34.240 in actuality there is like a millimeter's difference between where 0:09:34.240 --> 0:09:37.600 it is or even less. It's amazing. And that's the thing. 0:09:37.760 --> 0:09:40.320 If you did take your if you did take your 0:09:40.320 --> 0:09:42.000 hard drive and throw it on the floor, it is 0:09:42.120 --> 0:09:47.199 very possible that the head crashed into the platters, which 0:09:47.240 --> 0:09:51.240 is very bad. Right. If you ever hear a clicking 0:09:51.320 --> 0:09:53.640 noise from your hard drive, that usually means that the 0:09:53.720 --> 0:09:56.160 platters are out of alignment, or that the head is 0:09:56.160 --> 0:09:59.840 actually coming into contact, something is hitting against something else 0:09:59.840 --> 0:10:03.319 with then that physical mechanical device, and that means that 0:10:03.400 --> 0:10:06.800 it is breaking down. That that also means you should 0:10:06.840 --> 0:10:09.680 take that hard drive as soon as you can to 0:10:09.920 --> 0:10:13.680 a professional who can pull the data off of the 0:10:13.720 --> 0:10:16.439 hard drive, because the hard drive itself may or may 0:10:16.480 --> 0:10:19.320 not be uh you may or may not be able 0:10:19.320 --> 0:10:21.600 to repair it. So you definitely want to be able 0:10:21.640 --> 0:10:24.600 to retrieve the information. And the reason why we're even 0:10:24.640 --> 0:10:28.240 talking about this physical device is because you may have guessed, 0:10:28.240 --> 0:10:31.440 because you've got this mechanical element, it's going to take 0:10:31.520 --> 0:10:35.120 a lot longer to retrieve that information. Comparatively speaking, we're 0:10:35.120 --> 0:10:38.880 talking about milliseconds now as opposed to nanoseconds, and in 0:10:38.920 --> 0:10:42.199 the world of computers, that's a long time. You know, 0:10:42.240 --> 0:10:45.160 you're talking about these other fractions of a second, billions 0:10:45.160 --> 0:10:47.600 of a second and then several or you know, you 0:10:47.640 --> 0:10:51.000 go to a couple orders of magnitude up you realize 0:10:51.040 --> 0:10:52.880 this is this is a lot longer, and it's going 0:10:52.920 --> 0:10:56.319 to mean that in general, the operations that you start 0:10:56.400 --> 0:10:58.720 to use on your computer are going to take more 0:10:58.720 --> 0:11:01.199 and more time. Well, there are only so many ways 0:11:01.240 --> 0:11:05.280 we can limit how much time it takes to retrieve 0:11:05.280 --> 0:11:09.400 information from a hard drive. Some of that includes creating 0:11:09.440 --> 0:11:14.400 better interfaces, which is when we went from the two 0:11:14.440 --> 0:11:18.080 SATA interfaces s A T A interfaces. Uh, that was 0:11:18.080 --> 0:11:20.200 actually a big improvement. It meant that we could move 0:11:20.280 --> 0:11:24.880 data much more quickly from the hard drive into RAM. 0:11:25.000 --> 0:11:29.319 But there's only so so much faster you can go 0:11:29.760 --> 0:11:34.400 without really turning up that RPM speed to ludicrous amounts. 0:11:34.400 --> 0:11:36.120 And of course the faster it goes, the more likely 0:11:36.200 --> 0:11:39.480 you have mechanical problems down the line. I mean we're 0:11:39.480 --> 0:11:42.760 and tear and things of that nature. So, um, you 0:11:42.840 --> 0:11:46.440 have the incredibly reliable hard drive. I mean we've been 0:11:46.520 --> 0:11:49.400 using these things for years and years now. Um, they've 0:11:49.440 --> 0:11:52.800 gone up to very large sizes. Uh. And and they're 0:11:52.840 --> 0:11:56.160 they're fairly cheap compared to the way they were just 0:11:56.400 --> 0:11:59.920 a few years ago. But they have they have their 0:12:00.000 --> 0:12:02.520 own problems. I mean they're they're delicate. You can't necessarily 0:12:02.520 --> 0:12:05.520 take them everywhere, um, you know, and expect them to 0:12:05.600 --> 0:12:10.680 operate uh flawlessly. Um and uh you know, as you 0:12:10.840 --> 0:12:15.280 pointed out, they're they're only so fast. So uh. Flash 0:12:15.360 --> 0:12:19.439 memory in general is is, you know, an alternative, a 0:12:19.720 --> 0:12:23.239 very pleasant alternative. It works in our in our smartphones 0:12:23.280 --> 0:12:26.920 and our music players. Um, it works in in memory sticks, 0:12:26.920 --> 0:12:29.960 I mean thumb drives. You know, kids of all ages 0:12:30.000 --> 0:12:32.000 now take them to school with them because you know, 0:12:32.040 --> 0:12:35.800 that you can keep. Um I remember one gigabyte hard 0:12:35.880 --> 0:12:39.040 drives that were huge, and now you can keep sixteen 0:12:39.120 --> 0:12:41.720 gigs on a tiny thumb drive that cost you know, 0:12:41.760 --> 0:12:45.160 a very tiny fraction of the price. Spies. Spies use 0:12:45.240 --> 0:12:50.840 them to UH to put malware onto secure systems. Because 0:12:50.880 --> 0:12:54.760 both both stucks net and Flame appear to have been 0:12:54.880 --> 0:12:59.880 injected into target computers using UH and an off site 0:13:00.080 --> 0:13:03.360 sort of storage device. So some sort of well offsite 0:13:03.360 --> 0:13:06.360 from the computer system UH so something like a thumb drive. 0:13:06.440 --> 0:13:09.320 So you can imagine there's a guy who might have 0:13:09.320 --> 0:13:13.960 paid a little visit to an Iranian UH uranium enrichment 0:13:14.000 --> 0:13:16.640 plant and happen to have this thumb drive, plug it 0:13:16.640 --> 0:13:19.080 into a computer system and infected it that way. That's 0:13:19.120 --> 0:13:23.200 just one potential way that scenario could have unfolded. But yeah, 0:13:23.360 --> 0:13:28.040 I mean, these things have have become ubiquitous in all 0:13:28.080 --> 0:13:32.920 areas of computing, so why not make a hard drive 0:13:33.080 --> 0:13:37.040 out of the same sort of approach, Because it means 0:13:37.120 --> 0:13:39.880 that you're using instead of a mechanical system, you're using 0:13:39.880 --> 0:13:44.480 an integrated circuit in order to store information. You no 0:13:44.520 --> 0:13:48.760 longer have to worry about spinning platters or reading heads 0:13:48.840 --> 0:13:52.360 or anything like that you can really decrease the amount 0:13:52.360 --> 0:13:56.120 of time that that latency time, so that when you 0:13:56.200 --> 0:13:59.920 are pulling information from the hard drive, it's much close 0:14:00.040 --> 0:14:02.160 sirt to the speeds that you would see on the 0:14:02.200 --> 0:14:05.720 CPU die itself, or at least in the computer's memory 0:14:06.200 --> 0:14:09.160 as opposed to on a traditional hard drive. And before 0:14:09.160 --> 0:14:10.960 we get too far into this, I do want to 0:14:11.000 --> 0:14:14.520 say something about what some of the sources of information 0:14:14.559 --> 0:14:17.360 we pulled from. We do have a great article on 0:14:17.440 --> 0:14:20.840 how stuff works about how flash drives work, and a 0:14:20.840 --> 0:14:24.320 lot of the information applies to solid state drives. Yeah 0:14:24.320 --> 0:14:27.480 they're they're not exactly the same, but yeah, they're they're 0:14:27.520 --> 0:14:30.880 kind of principles, are there. Yeah, they're close cousins, because 0:14:31.080 --> 0:14:33.640 a lot of the things that go into what make 0:14:33.680 --> 0:14:37.360 flash drives work apply to solid state drives. But an 0:14:37.520 --> 0:14:42.040 excellent resource on the web is an Ours Technica series, 0:14:42.360 --> 0:14:44.560 one of which one of the articles in that series 0:14:44.640 --> 0:14:48.560 is called solid State Revolution in Depth on how s 0:14:48.560 --> 0:14:52.360 s d s Really work by Lee Hutchinson. And I 0:14:52.440 --> 0:14:55.600 can't say enough good things about this article. It really 0:14:55.720 --> 0:14:59.640 is a comprehensive approach to how solid state drives work. 0:15:00.080 --> 0:15:04.080 End there's a little, uh, little latitude in the article, 0:15:04.160 --> 0:15:06.880 so it makes it it's not it's not dry reading. No, well, 0:15:06.920 --> 0:15:10.480 our our technical is like that. UM. It's also just 0:15:10.480 --> 0:15:13.800 just as a note, it's also very technical in spots too, 0:15:13.920 --> 0:15:17.120 So if you know, it's it's a they that site. 0:15:17.200 --> 0:15:20.600 It takes a little bit different approach to technology than 0:15:20.680 --> 0:15:23.080 than we do in a good way. It's at a 0:15:23.160 --> 0:15:26.280 different level. So it's it's it's definitely more serious if 0:15:26.320 --> 0:15:29.640 you if you're already familiar. Yeah, if you're already familiar 0:15:29.680 --> 0:15:33.600 with UM, with computer architecture and data and that sort 0:15:33.600 --> 0:15:37.400 of thing. Uh, it's an excellent resource. Otherwise, it may 0:15:37.480 --> 0:15:41.240 it may feel a little advanced for someone who is 0:15:41.600 --> 0:15:45.960 just curious about this but doesn't have any real background. However, 0:15:46.360 --> 0:15:50.680 it's well worthy read. So getting back to solid state drives, So, 0:15:51.160 --> 0:15:55.040 the idea of creating a solid state drive, uh was 0:15:55.080 --> 0:15:59.680 really really attractive because of that decreased latency. UM. There 0:15:59.720 --> 0:16:03.000 were some challenges, of course, because solid state drives they 0:16:03.040 --> 0:16:09.240 do not store information magnetically the way traditional hard drives do. No. Now, 0:16:09.280 --> 0:16:12.800 actually it sort of reminds me of electronic ink in 0:16:12.840 --> 0:16:16.640 a way. Interesting. Well, if you know something about electronic ink, 0:16:16.680 --> 0:16:21.080 you know that the capsules white or black generally are 0:16:21.120 --> 0:16:25.840 stored in between a sandwich of h material that holds 0:16:25.920 --> 0:16:29.160 a positive or negative charge, and that's how it reads 0:16:29.160 --> 0:16:32.120 a page. But once the page is there, it stays there. 0:16:32.360 --> 0:16:35.280 I see. So you're thinking of that as for it. 0:16:35.400 --> 0:16:38.200 Let's just say, for example, that the black parts of 0:16:38.240 --> 0:16:41.360 the screen are ones and the white parts are zeros, 0:16:41.760 --> 0:16:45.200 and they retain that even when the power is off, 0:16:45.240 --> 0:16:48.280 so they're non volatile. Right. That means that when you 0:16:48.320 --> 0:16:52.720 remove the power source from this system, it keeps that information. Now, 0:16:52.800 --> 0:16:54.920 that of course is extremely important when it comes to 0:16:54.920 --> 0:16:58.800 computers because, like Chris was saying, RAM is volatile memory. 0:16:59.800 --> 0:17:04.000 If you lose that power, then that information goes away. 0:17:04.080 --> 0:17:06.720 There's no longer a charge to maintain the information that 0:17:06.880 --> 0:17:09.720 stored in your computer's memory. You don't want that to 0:17:09.760 --> 0:17:11.680 happen to your hard drive because that means that every 0:17:11.680 --> 0:17:14.119 time you would turn off your computer or lose power, 0:17:14.480 --> 0:17:16.800 you would lose all the data stored there. You have 0:17:16.880 --> 0:17:21.360 to have non volatile memory to keep storage a possibility. 0:17:21.760 --> 0:17:25.360 Well nice, yeah, because I mean the old, the old, old, 0:17:25.400 --> 0:17:28.080 old computers that that Chris and I worked on didn't 0:17:28.119 --> 0:17:31.879 have hard drives. You had to store things on magnetic discs. 0:17:32.480 --> 0:17:34.520 H If you turned your computer on, it just went 0:17:34.600 --> 0:17:37.439 to its initial state. The only thing that was stored 0:17:37.480 --> 0:17:39.840 on there was the operating system because it was written 0:17:39.880 --> 0:17:42.520 in read only memory, which was non volatile, but it 0:17:42.560 --> 0:17:47.400 was also unchangeable. You couldn't write to it. So that 0:17:47.440 --> 0:17:49.680 meant that, you know, if you want to write a program, 0:17:49.720 --> 0:17:51.520 you had to store it on a disk, because if 0:17:51.520 --> 0:17:53.280 you tried to write it just on your computer, you 0:17:53.320 --> 0:17:54.639 didn't have a disk in there, and you turned the 0:17:54.640 --> 0:17:57.040 computer off, all your work has gone. This is also 0:17:57.160 --> 0:17:59.320 why if you've ever worked on a computer, and you've 0:17:59.320 --> 0:18:03.480 ever heard anyone say save your work, often that's why 0:18:03.560 --> 0:18:05.840 when you save your work, it's being saved to your 0:18:05.880 --> 0:18:08.560 hard drive, not to your computer's memory. So if you're 0:18:08.560 --> 0:18:10.520 working on something and you haven't saved it in a while, 0:18:11.000 --> 0:18:13.840 it may only exist in your computer's memory. If power 0:18:13.880 --> 0:18:16.199 goes out, you may lose all that work. As I 0:18:16.280 --> 0:18:19.760 have done on multiple occasions. I was actually in my 0:18:19.800 --> 0:18:25.400 college's computer lab during a storm and the screams out. 0:18:25.520 --> 0:18:29.240 There's nothing like working in any sort of computer environment 0:18:29.320 --> 0:18:31.560 when the power goes out and then you hear there's 0:18:31.680 --> 0:18:35.359 there's usually about a second and a half delay between 0:18:35.400 --> 0:18:39.440 the power going out and every single person making essentially 0:18:39.480 --> 0:18:45.160 the same noise, which sounds like this. Ah, I leaned 0:18:45.160 --> 0:18:47.000 back as I did that, so there was a little 0:18:47.000 --> 0:18:51.080 Doppler effect. But anyway, so yeah, this, this sort of 0:18:51.080 --> 0:18:55.240 of non volatile memory means that that information is going 0:18:55.280 --> 0:18:57.600 to stay there even when you turn the power off. 0:18:57.600 --> 0:18:59.920 This is the exact same sort of stuff we find 0:19:00.080 --> 0:19:04.680 in our MP three players and other mobile devices that 0:19:04.960 --> 0:19:07.560 because again, if we didn't have that, then every time 0:19:07.600 --> 0:19:10.120 you turned off your MP three player you would lose 0:19:10.160 --> 0:19:12.320 your entire library of songs. You have to reload it 0:19:12.359 --> 0:19:14.639 the next time you turn it on, right, right, Well, 0:19:14.680 --> 0:19:19.399 there is um to to complete my analogy. Yes, along 0:19:19.440 --> 0:19:26.280 with the electronic ink thing, the flash memory also uses cells. Um. 0:19:26.359 --> 0:19:30.439 It stores information in in cells, and that cell is 0:19:30.480 --> 0:19:33.119 either a one or a zero. Right to think of 0:19:33.119 --> 0:19:36.119 the cells like a sheet of grid paper. Yes, and 0:19:36.960 --> 0:19:40.520 you've got rows and you've got columns. Right, So the 0:19:40.760 --> 0:19:43.959 rows of cells. If you took one row of cells, 0:19:44.119 --> 0:19:47.240 we would call that in in solid state drive terminology, 0:19:47.320 --> 0:19:50.520 that would be a page. So one row of the 0:19:50.920 --> 0:19:52.880 cells would be a page, and then you would have 0:19:53.280 --> 0:19:56.200 several rows of cells and several columns of cells that 0:19:56.240 --> 0:19:59.840 would form what is called a block. And this is 0:20:00.000 --> 0:20:02.880 really important because it comes down to the way information 0:20:03.280 --> 0:20:07.080 is written and erased. In solid state drives. It turns 0:20:07.119 --> 0:20:12.800 out that you cannot individually change the cells within that 0:20:13.320 --> 0:20:15.000 grid paper. For example, if you if you had a 0:20:15.040 --> 0:20:16.800 sheet of grid paper in front of you, you could 0:20:16.800 --> 0:20:19.480 write a one or a zero and every single grid 0:20:19.880 --> 0:20:21.639 and if you wanted to, if you're writing in pencil, 0:20:21.680 --> 0:20:25.880 you could erase a single cell and change that one 0:20:25.920 --> 0:20:28.760 to a zero or zero to a one. You cannot 0:20:28.800 --> 0:20:31.680 do that with a solid state drive. We'll get into 0:20:31.720 --> 0:20:33.399 that in a little bit, but that's an important thing 0:20:33.440 --> 0:20:36.919 to think about from the start. Well, if you know 0:20:37.080 --> 0:20:41.120 something about hard drives, the the magnetic platter hard drives 0:20:41.600 --> 0:20:44.560 um when you when your computer, and that pretty much 0:20:44.560 --> 0:20:48.280 goes for all modern operating systems. Let's say you have 0:20:48.960 --> 0:20:52.439 a document and you realize that, well, you worked on 0:20:52.480 --> 0:20:55.560 it three years ago, You've turned it in. You know, 0:20:55.600 --> 0:20:57.159 I don't need to save it for anything, So I'm 0:20:57.200 --> 0:20:59.520 going to delete it, and I'm gonna tell my computer 0:20:59.560 --> 0:21:03.280 delete all that. First of all, the computer doesn't delete 0:21:03.280 --> 0:21:05.320 it deleted if you just tell it to, you know, 0:21:05.520 --> 0:21:07.240 throw it in the trash can, empty the trash can 0:21:07.320 --> 0:21:09.800 or recycle bin or whatever. It's actually still there on 0:21:09.880 --> 0:21:13.360 your hard drive, but it's been marked for deletion. So basically, 0:21:13.400 --> 0:21:16.680 when uh something else, Hey, I've created a new document 0:21:16.880 --> 0:21:20.000 and the computer goes, where can I say, ah, this 0:21:20.080 --> 0:21:24.919 is marked for deletion. I'll write over that old one. Um. 0:21:24.960 --> 0:21:27.680 That's one thing to note is that it can do that. 0:21:27.680 --> 0:21:31.320 That's the way that that computers work with magnetic platter 0:21:31.440 --> 0:21:34.680 hard drives. Now it also can do something else. Let's 0:21:34.680 --> 0:21:37.560 say you have five different documents and you've deleted these 0:21:37.600 --> 0:21:42.480 five documents. Well, those gaps are different sizes, but you're 0:21:42.680 --> 0:21:45.000 storing a brand new file and it's larger than all 0:21:45.000 --> 0:21:48.159 five of those. It can fill in sections, sort of 0:21:48.160 --> 0:21:50.919 like packets when you send when you break up an 0:21:50.920 --> 0:21:52.720 email file into a bunch of packets and they go 0:21:52.760 --> 0:21:55.879 and they reassemble themselves on the other side on somebody 0:21:55.880 --> 0:22:00.119 else's computer. These different gaps can be used to or 0:22:00.320 --> 0:22:04.000 parts of this file, which the computer will then reassemble 0:22:04.080 --> 0:22:06.600 as you need it. Um, that's when you need to 0:22:06.640 --> 0:22:10.119 fragment your hard drive. You know, they have uh sections 0:22:10.160 --> 0:22:12.679 and they're all scattered out. You've got applications, and then 0:22:12.760 --> 0:22:15.560 they're all in different places, in different sectors on different 0:22:15.560 --> 0:22:19.720 platters um, and they say, okay, I'm going to reorganize everything. 0:22:20.320 --> 0:22:24.080 And so the computer basically uses storage empty storage to 0:22:25.040 --> 0:22:27.919 reshuffle everything and put it back into sectors where all 0:22:27.920 --> 0:22:30.760 the parts of the filer together. And that makes a 0:22:30.760 --> 0:22:33.200 computer run a little bit faster when it's accessing those 0:22:33.200 --> 0:22:34.919 files because they're on one place and they don't have 0:22:34.960 --> 0:22:39.040 to reassemble them. Now, you can't do that with uh, 0:22:39.160 --> 0:22:41.840 solid state drives yea. In fact, when it gets down 0:22:41.880 --> 0:22:44.640 to a racing data off a solid state drive, it's 0:22:45.359 --> 0:22:49.120 pretty pretty complex. But before we get into that, let's 0:22:49.160 --> 0:22:50.840 talk a little bit, a little a little bit more 0:22:50.840 --> 0:22:54.080 about the way information is stored within these cells, so 0:22:54.160 --> 0:22:56.000 these grids on your grid paper. Yeah, I just thought 0:22:56.000 --> 0:22:58.760 it would be interesting to compare that to a platter 0:22:58.840 --> 0:23:01.680