WEBVTT 00:00:00.000 --> 00:00:04.360 What is Oculink? It sounds like the tech that Dr. Octopus uses 00:00:04.360 --> 00:00:10.040 to control his robot arms, legs, but it's actually an open standard PCI Express connector 00:00:10.040 --> 00:00:14.600 with a compact form factor created to compete with Thunderbolt and USB. 00:00:14.600 --> 00:00:20.440 Despite being around for nearly a decade, Oculink has remained a relatively obscure standard, 00:00:20.440 --> 00:00:23.560 which is a shame because it's actually pretty awesome. 00:00:23.560 --> 00:00:28.720 Oculink stands for optical copper link and was initially envisioned as a combination 00:00:28.720 --> 00:00:33.040 of copper and optical fiber. However, the need to convert electrical signals 00:00:33.040 --> 00:00:37.940 into light signals and back again means that fiber optics are relatively inefficient 00:00:37.940 --> 00:00:42.440 over short distances. So the whole optical element was eventually scrapped, 00:00:42.440 --> 00:00:46.800 though the name remains. CU stands for copper's chemical symbol, 00:00:46.800 --> 00:00:52.280 which is itself based on copper's Latin name. Otherwise, it would be spelled acolink, 00:00:52.280 --> 00:00:56.360 and I think we can all agree that's just terrible. Aco, acolink? 00:00:56.440 --> 00:00:59.560 Oculink was developed by PCI SIG, 00:00:59.560 --> 00:01:03.240 the body charged with creating standards for the PCI interface. 00:01:03.240 --> 00:01:07.920 Oculink 2.0, the most recent version, launched in 2017 with a new connector, 00:01:07.920 --> 00:01:14.160 similar to the standard DisplayPort connector. It boasts support for up to four PCIe 4.0 lanes 00:01:14.160 --> 00:01:20.200 and up to eight gigabits per second per lane for a total of 64 gigabits per second of bandwidth, 00:01:20.200 --> 00:01:23.440 though notably an eight lane version also exists. 00:01:23.440 --> 00:01:27.380 That places the four lane version above both Thunderbolt 3 and 4 00:01:27.380 --> 00:01:31.980 in terms of transmission speed and on par with Intel's upcoming Thunderbolt 5, 00:01:31.980 --> 00:01:37.540 which is supposed to launch sometime in 2024 with 80 gigabits per second of bi-directional bandwidth, 00:01:37.540 --> 00:01:40.940 but only 64 gigabits per second of PCIe bandwidth. 00:01:40.940 --> 00:01:46.260 Now beyond bandwidth, a primary advantage of Oculink is that it's far more cost effective. 00:01:46.260 --> 00:01:49.700 That was particularly the case prior to 2018 00:01:49.700 --> 00:01:55.700 when Thunderbolt became a royalty-free standard, but it's still true, albeit to a lesser degree, 00:01:55.700 --> 00:01:59.740 simply because it uses cheaper components and doesn't require quite the same amount 00:01:59.740 --> 00:02:03.800 of precision to manufacture. It's that combination of high performance 00:02:03.800 --> 00:02:08.020 and a lower price point, which has garnered Oculink a devoted following, 00:02:08.020 --> 00:02:13.060 especially on the server side. Now that doesn't mean there's no consumer side applications. 00:02:13.060 --> 00:02:19.060 Oculink reduces the performance gap between internal and external GPUs to a very low margin 00:02:19.060 --> 00:02:24.940 because it's significantly faster than Thunderbolt 3 or 4. What Oculink doesn't do, that Thunderbolt does, 00:02:24.940 --> 00:02:29.740 is provide solid support for hot plugging. With Oculink, you're typically going to want 00:02:29.740 --> 00:02:33.900 to shut down the system before swapping components, or it might crash. 00:02:33.900 --> 00:02:38.500 Oculink only uses PCIe signals, making it great for connecting a graphics card, 00:02:38.500 --> 00:02:43.780 network card, or storage controller, but Thunderbolt is basically a two-in-one DisplayPort 00:02:43.780 --> 00:02:46.860 slash PCIe connector, which can provide video 00:02:46.860 --> 00:02:51.660 in addition to power and data transfer. Oculink only transfers data, 00:02:51.660 --> 00:02:56.420 so an Oculink setup is always going to need at least two cables if you want to connect 00:02:56.420 --> 00:03:00.980 and power a device at the same time. Not to mention that Thunderbolt ports are compatible 00:03:00.980 --> 00:03:06.420 with USB-C cables. These factors, plus having daddy Intel as a backer, 00:03:06.420 --> 00:03:11.020 mean that Thunderbolt has much broader adoption in the consumer electronic space. 00:03:11.020 --> 00:03:14.140 And that ubiquity gives Thunderbolt a definite advantage 00:03:14.140 --> 00:03:17.780 in terms of convenience, especially for less tech-savvy users. 00:03:17.780 --> 00:03:23.220 Now, you could, hypothetically, create a version of Oculink with some or all 00:03:23.220 --> 00:03:27.500 of the bells and whistles that Thunderbolt offers, but that might be missing out 00:03:27.500 --> 00:03:30.540 on what makes Oculink truly great. 00:03:30.540 --> 00:03:35.900 Thunderbolt is designed to be a generalist connector, a jack of all jacks, if you will. 00:03:35.900 --> 00:03:41.540 It's made to do several different things quite well, wrapped up in a convenient user-friendly package, 00:03:41.540 --> 00:03:45.580 but generalization comes at the expense of specialization, 00:03:45.580 --> 00:03:50.020 and lower data transfer speeds and throttling are a result of that compromise. 00:03:50.020 --> 00:03:53.340 A similarly flexible and multi-purpose Oculink connector 00:03:53.340 --> 00:03:59.020 would also probably be far more expensive, because when you're combining a bunch of complex components 00:03:59.020 --> 00:04:02.860 exchanging a bunch of different signals in a very, very small space, 00:04:02.860 --> 00:04:08.220 that demands both creative engineering and extremely precise manufacturing. 00:04:08.220 --> 00:04:12.460 Otherwise, there's gonna be interference between these different signals, and it won't be reliable. 00:04:12.460 --> 00:04:16.660 Thunderbolt 5 is supposed to give us the best of both worlds, 00:04:16.660 --> 00:04:20.020 the convenience and versatility of earlier versions of Thunderbolt, 00:04:20.020 --> 00:04:23.020 but with far faster data transfer speeds. 00:04:23.020 --> 00:04:28.340 It'll be a while before we can see real-world benchmarks, but I mean, that sounds awesome. 00:04:28.340 --> 00:04:32.700 It bears remembering, however, that so long as these connectors remain a bottleneck, 00:04:32.700 --> 00:04:37.900 and performance loss is non-trivial, there will always be space for an improved version 00:04:37.900 --> 00:04:42.860 of the Oculink or another specialized connector to come along and do it better. 00:04:42.860 --> 00:04:46.500 Here's open, cheers. 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