WEBVTT 00:00:00.000 --> 00:00:03.040 Although we still haven't gotten PCI express 5.0 devices 00:00:03.040 --> 00:00:07.960 in our hot little hands yet, believe it or not, the PCIe 6.0 specification 00:00:07.960 --> 00:00:12.360 has already been released. And as you may have guessed, it's insanely fast. 00:00:12.360 --> 00:00:16.600 At 126 gigabytes per second one way on an X16 link, 00:00:16.600 --> 00:00:21.040 it's twice as fast as 5.0, four times as fast as 4.0, 00:00:21.040 --> 00:00:25.720 which is fairly new on the market, and eight times faster than the 3.0 devices 00:00:25.720 --> 00:00:27.920 many of us idiots are currently using. 00:00:28.920 --> 00:00:34.240 But how do they make it so fast? And more importantly, does it have real relevance for you, the home user, 00:00:34.240 --> 00:00:38.340 or is it just overkill? To find out, we spoke with Dibendra Dash Sharma, 00:00:38.340 --> 00:00:42.800 an Intel fellow in their data platforms group, and we'd like to thank him for lending his time 00:00:42.800 --> 00:00:47.960 and expertise. So unsurprisingly, PCI express 6.0 is backwards compatible 00:00:47.960 --> 00:00:53.320 with all the previous generations of PCIe, but if you go all the way back to version 1.0, 00:00:53.320 --> 00:00:58.400 you could only get up to four gigabytes per second one way from an X16 slot. 00:00:58.400 --> 00:01:02.080 Now, we're pushing 32 times as much data 00:01:02.080 --> 00:01:06.480 through the same link. Older revisions of PCIe express got faster and faster 00:01:06.480 --> 00:01:11.260 because they increased their transmission frequencies, but it turns out you can only do this so much 00:01:11.260 --> 00:01:16.400 before the signal becomes super unstable. It's kind of similar to how a 5 gigahertz Wi-Fi connection 00:01:16.400 --> 00:01:21.080 is faster than a 2.4 gig link, but it's also not as stable at long distances. 00:01:21.080 --> 00:01:25.280 So instead, PCIe 6 uses a technique called PAM4, 00:01:25.320 --> 00:01:30.120 which can actually carry two bits of data at the same time instead of just one. 00:01:30.120 --> 00:01:33.240 Unlike traditional signaling, where one voltage represented a zero 00:01:33.240 --> 00:01:37.840 and a second voltage represented a one, PAM4 uses four different voltages, 00:01:37.840 --> 00:01:42.840 and each one corresponds to either 00, 01, 10, or 11, 00:01:43.080 --> 00:01:47.360 meaning twice as much data is sent per unit of time. 00:01:47.360 --> 00:01:52.660 However, shoving more stuff through the pipes is, just like in regular life, not the greatest idea. 00:01:52.660 --> 00:01:57.420 In this case, it increases the rate of errors, and even with the PCIe special interest group 00:01:57.420 --> 00:02:01.940 adding a few nanoseconds of latency to reduce the error rate to about one bit per million, 00:02:01.940 --> 00:02:05.940 that's still a lot of potential errors when you consider how much data flows 00:02:05.940 --> 00:02:11.120 through a typical PCIe express link. However, a few bytes in each chunk of data that's sent 00:02:11.120 --> 00:02:16.260 are reserved for error checking and correction. If the receiving device sees that a packet is incorrect, 00:02:16.260 --> 00:02:19.460 it can ask for it again using just a few bytes of data. 00:02:19.460 --> 00:02:24.380 Because this error correcting scheme is quite lightweight, it only adds a very small amount of latency. 00:02:24.380 --> 00:02:27.940 So this way, PCIe 6.0 can operate at very high speeds 00:02:27.940 --> 00:02:32.900 without constantly losing signal integrity. In fact, it's estimated that instead of an error rate 00:02:32.900 --> 00:02:36.080 of one bit in a million, PCIe 6.0 can operate 00:02:36.080 --> 00:02:40.800 with only one unfixed error every billion, billion hours. 00:02:40.800 --> 00:02:46.060 So you'll probably never have to worry about it unless you're an elf from Middle Earth. 00:02:46.060 --> 00:02:49.680 But Riley, hold on a minute. All this performance is fine and good, 00:02:49.680 --> 00:02:54.440 but my graphics card doesn't even saturate the PCIe express slot in my computer today. 00:02:54.440 --> 00:02:58.600 Why should I care about this? Well, one reason is that as we continue to ask 00:02:58.600 --> 00:03:02.440 for more and more out of our devices, having the fattest pike possible, 00:03:04.440 --> 00:03:11.480 will ensure that we can do things like hit our SSDs with mega-sized downloads, stream 4K and 8K HDR video, 00:03:11.480 --> 00:03:16.460 and keep up with the ever-increasing demands video games put on our graphics cards all at the same time. 00:03:16.460 --> 00:03:20.600 But going beyond just your home PC, think of all the cloud services you utilize 00:03:20.640 --> 00:03:23.680 on a daily basis for applications from voice assistance 00:03:23.680 --> 00:03:28.400 to IoT devices to self-driving cars. Well, assuming you can afford one. 00:03:28.400 --> 00:03:33.180 All these gadgets need a high bandwidth interface that can process data with minimal latency. 00:03:33.180 --> 00:03:38.600 Think of an autonomous car that quickly has to get data from a camera to a CPU to a 5G modem, 00:03:38.600 --> 00:03:43.400 which then goes into a server somewhere that has to respond quickly to aid and hazard recognition 00:03:43.400 --> 00:03:46.840 and is also moving data around internally for machine learning. 00:03:46.840 --> 00:03:50.320 That's a lot of data. On both ends of that connection, 00:03:50.320 --> 00:03:55.080 PCI-Express 6.0 could deliver enough speed to make the experience seamless 00:03:55.080 --> 00:03:59.320 and maybe even tell you about an icy road ahead before you end up in the ditch. 00:03:59.320 --> 00:04:03.520 All right, that's it for this video, guys. Thanks for watching. Like the video if you liked it. 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