PCI-SIG Finalizes PCIe 5.0 Specification: x16 Slots to Reach 64GB/sec
Following the long gap after the release of PCI Express 3.0 in 2010, the PCI Special Interest Group (PCI-SIG) set about a plan to speed up the development and release of successive PCIe standards. Following this plan, in late 2017 the group released PCIe 4.0, which doubled PCIe 3.0's bandwidth. Now less than two years after PCIe 4.0 – and with the first hardware for that standard just landing now – the group is back again with the release of the PCIe 5.0 specification, which once again doubles the amount of bandwidth available over a PCI Express link.
Built on top of the PCIe 4.0 standard, the PCIe 5.0 standard is a relatively straightforward extension of 4.0. The latest standard doubles the transfer rate once again, which now reaches 32 GigaTransfers/second. Which, for practical purposes, means PCIe slots can now reach anywhere between ~4GB/sec for a x1 slot up to ~64GB/sec for a x16 slot. For comparison's sake, 4GB/sec is as much bandwidth as a PCIe 1.0 x16 slot, so over the last decade and a half, the number of lanes required to deliver that kind of bandwidth has been cut to 1/16th the original amount.
Previously:
PCIe 4.0 to be Available This Year, PCIe 5.0 in 2019
Version 0.9 of the PCI Express 5.0 Specification Ratified
Obligatory xkcd
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http://www.tomshardware.com/news/pcie-4.0-5.0-pci-sig-specfication,35325.html
PCIe is the ubiquitous engine that pulls a big part of the computing locomotive down the track—it touches nearly every device in your computer. As such, it is the linchpin for the development of many other technologies, such as storage, networking, GPUs, chipsets, and many other devices. Considering its importance, it isn't surprising to find the PCI-SIG with 750 members worldwide. Unfortunately, large organizations tend to move slowly, and PCIe 4.0 is undoubtedly late to market. PCIe 3.0 debuted in 2010 within the normal four-year cadence, but PCIe 4.0 isn't projected to land in significant quantities until the end of 2017—a seven-year gap.
PCI-SIG representatives attributed part of the delay to industry stagnation. The PCIe 3.0 interface was sufficient for storage, networking, graphics cards, and other devices, for the first several years after its introduction. Over the last two years, a sudden wellspring of innovation exposed PCIe 3.0's throughput deficiencies. Artificial intelligence craves increased GPU throughput, storage devices are migrating to the PCIe bus with the NVMe protocol, and as a result, networking suddenly has an insatiable appetite for more bandwidth.
The industry needs PCIe 4.0 to land soon, and PCI-SIG assures us it will ratify the new specification by the end of 2017. The sluggish ratification process hasn't hampered adoption entirely, though. Several IP vendors already offer 16GT/s controllers, and many vendors have already implemented PCIe 4.0 PHYs into their next-generation products. These companies are plowing ahead with the 0.9 revision of the specification, whereas the final ratified spec debuts at 1.0. PCI-SIG says it is accelerating the development and feedback processes, along with simplifying early specification revisions, in a bid to reduce time to market for future specifications. PCI-SIG indicates that PCIe 4.0 will be a short-lived specification because the organization has fast-tracked PCIe 5.0 for final release in 2019.
[...] AMD has slated PCIe 4.0 for 2020. We imagine Intel is also chomping at the bit to deploy PCIe 4.0 3D XPoint and NVMe SSDs, but the company remains silent on its timeline.
The industry has been stuck on PCIe 3.0 for roughly seven years, and even though the first support for PCIe 4.0 on the desktop will land soon in AMD's third-gen Ryzen chips and the first PCIe 4.0 SSDs just cropped up, the industry is already adopting PCIe 5.0. The new standard doubles throughput over PCIe 4.0, yielding a data rate of 32 GT/s.
Today PCI-SIG, the organization that defines PCIe standards, announced that it ratified Version 0.9 of the PCI Express 5.0 specification, signaling that end devices will come to market in the near future. (Companies design end devices as early as revision 0.4 and often launch with 0.9.)
[...] PCIe 4.0 brings 64GBps of throughput, while PCIe 5.0 will double that to 128GBps. Both revisions still use the 128b/130b encoding scheme that debuted with PCIe 3.0. PCI-SIG representatives said they are satisfied with the 20% reduction in overhead facilitated by the 128b/130b encoding, and further encoding refinements to reduce the current 1.5% overhead are subject to a diminishing point of returns.
PCIe 5.0 also brings other features, like electrical changes to improve signal integrity, backward-compatible CEM connectors for add-in cards, and backward compatibility with previous versions of PCIe. The PCI-SIG also designed the new standard to reduce latency and tolerate higher signal loss for long-reach applications.
Previously: PCIe 4.0 to be Available This Year, PCIe 5.0 in 2019
PCI Express Bandwidth to Be Doubled Again: PCIe 6.0 Announced, Spec to Land in 2021
When the PCI Special Interest Group (PCI-SIG) first announced PCIe 4.0 a few years back, the group made it clear that they were not just going to make up for lost time after PCI 3.0, but that they were going to accelerate their development schedule to beat their old cadence. Since then the group has launched the final versions of the 4.0 and 5.0 specifications, and now with 5.0 only weeks old, the group is announcing today that they are already hard at work on the next version of the PCIe specification, PCIe 6.0. True to PCIe development iteration, the forthcoming standard will once again double the bandwidth of a PCIe slot – a x16 slot will now be able to hit a staggering 128GB/sec – with the group expecting to finalize the standard in 2021.
[...] PCIe 6.0, in turn, is easily the most important/most disruptive update to the PCIe standard since PCIe 3.0 almost a decade ago. To be sure, PCIe 6.0 remains backwards compatible with the 5 versions that have preceded it, and PCIe slots aren't going anywhere. But with PCIe 4.0 & 5.0 already resulting in very tight signal requirements that have resulted in ever shorter trace length limits, simply doubling the transfer rate yet again isn't necessarily the best way to go. Instead, the PCI-SIG is going to upend the signaling technology entirely, moving from the Non-Return-to-Zero (NRZ) tech used since the beginning, and to Pulse-Amplitude Modulation 4 (PAM4).
[...] PCIe 6.0 will be able to reach anywhere between ~8GB/sec for a x1 slot up to ~128GB/sec for a x16 slot (e.g. accelerator/video card). For comparison's sake, 8GB/sec is as much bandwidth as a PCIe 2.0 x16 slot, so over the last decade and a half, the number of lanes required to deliver that kind of bandwidth has been cut to 1/16th the original amount.
Previously: PCIe 4.0 to be Available This Year, PCIe 5.0 in 2019
Version 0.9 of the PCI Express 5.0 Specification Ratified
PCIe 5.0 Specification Finalized (yes, that was 3 weeks ago)
(Score: 2) by EEMac on Friday May 31 2019, @02:14PM
Okay, that's a pretty huge (16x) bandwidth jump over PCIe 1.0. Those 1x PCIe cards have never had it so good!
(Score: 0) by Anonymous Coward on Friday May 31 2019, @03:14PM (6 children)
This seems like a designed forced upgrade cycle process to make more money for hardware manufacturers. Just like TVs. HD (1090p), then 3D, then 4k, and now 8k. But a new TV every cycle, please, so we can maintain our profits (ignore the fact your current TV is perfectly good and doesn't need to be upgraded). It's the same with this. How many people need more bandwidth? Any why not have extended cycles where hardware and consumers can catch up and have a reasonable device lifetime? 2 years is too short, and creates a rush to replace that is just not needed. A 5 year cycle with bigger jumps would be better, but not for the hardware manufacturers as they won't have as many new and shiny things to convince people to buy.
(Score: 3, Informative) by takyon on Friday May 31 2019, @03:19PM
Gigabyte's next-gen SSD shows the incredible potential of PCIe 4.0 [engadget.com]
Aorus announces NVMe PCIe Gen 4 SSDs with 5 GB/s read speeds [notebookcheck.net]
One solution would be to skip certain iterations yourself. Skip from DDR3 based systems to DDR5, for example.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 2, Informative) by Anonymous Coward on Friday May 31 2019, @05:48PM (1 child)
Forced upgrade?
Every version of PCIe is backward and forward compatible, both for motherboards and expansion cards. It is the one of the least upgrade forcing standards ever created.
(Score: 2) by bob_super on Friday May 31 2019, @06:35PM
And getting twice the bandwidth is a wonderful upgrade for high-end gaming and SSDs.
That 4GHz processor of yours spends a lot of its time waiting for its caches to cycle the right data in and out. 2x the bandwidth is a good upgrade
My worry is that 16Gb/s is becoming easier, but 32Gb/s is still pretty hard, especially in pluggable form. I expect lots of early peripherals to have BER issues, either from cheap PCB/chips/caps design, or from end-users not realizing how important it is to mate clean connectors very carefully at those rates.
Question: I know PCIe 3 (8Gb/s) failing startup falls back to 1 (2.5G) instead of 2 (5G), for reasons I never understood. How about 4 (16G) and 5 (32G) ? How fast will those run until users realize they need to fix their hardware ?
(Score: 2) by jasassin on Friday May 31 2019, @11:19PM
I'm still using an e2180 CPU with PCI express 1.5. I'll continue to use this until the CPU or motherboard dies. Having better and faster hardware available as soon as possible is always a good thing. Why would you want to impede hardware improvements? That's just dumb.
jasassin@gmail.com GPG Key ID: 0xE6462C68A9A3DB5A
(Score: 2) by kazzie on Saturday June 01 2019, @08:51AM (1 child)
So how come your HDTV gets an extra 10 rows of pixels?
(Score: 0) by Anonymous Coward on Sunday June 02 2019, @07:17AM
Witchcraft is the only explanation.
(Score: 0) by Anonymous Coward on Friday May 31 2019, @03:34PM
Fuck'em all, I am going straight to ... oh.
(Score: 0) by Anonymous Coward on Friday May 31 2019, @03:38PM (1 child)
I've been waiting almost four years for PCIE 4.0. It has been delayed over and over and over again. I put off buying new hardware for almost two years because it was "almost ready."
I won't wait for PCIE 5.0.
(Score: 0) by Anonymous Coward on Friday May 31 2019, @05:28PM
But you are correct that the peripheral hardware has been harder to find.
I think Nvidia has some out that is supported by the aforementioned Power 9 hardware, but only on some lanes.
(Score: 1, Insightful) by Anonymous Coward on Friday May 31 2019, @11:58PM
I may upgrade to zen2 + PCIe4 but i'll be waiting for a while to do it. I may see if i can make it until PCIe5. I'm not real thrilled with AMD's lack of respect for our security with their closed source firmware, PSP, backdoors, etc. At least provide a way to verifiably opt out of that shit and still use your processors. i may save up for the next Power iteration instead. Or a riscv setup if i can wait that long. Tired of these suited slavemasters.