PCI-SIG Announces "CopprLink" PCI Express Cable Name

[illwieckz]

Note this is announced during a supercomputing conference.

I very much doubt it's a consumer technology based on USB-C. We already have USB 4 and Thunderbolt for that.

There's been increasing pressure to move GPUs and other PCIe devices inside servers onto cables. The higher signalling frequency of PCIe 5 seriously restricts PCB trace length without expensive redriver chips. Future revisions will be even worse. A shielded cable can be far longer without needing active components.

The sheer number of PCIe lanes from recent server CPUs (140 on latest Epyc) is an issue too. There isn't space to fill the board with PCIe x16 slots and their traces especially since it's needed for ever more DIMMs and memory channels. Daughterboards only exacerbate the signal integrity problem.

I'm almost certain this will be a new standard somewhat similar to U.2, for use inside server chassis and between units in racks. It'll support x16, either directly or by supporting multiple cables in parallel. It won't compete with Thunderbolt for consumer use.

That would be perfect: remove all the x16 slots and maybe just put non-wired x1 slots just to keep the card in place (or just provide power for lower end devices), and expect the user to wire the card with such PCIe cable like we already wire the power.

[phoenix_rizzen]

While it came first, right now thunderbolt is more or less a certified and tested compliant version of USB.

Thunderbolt 3 became USB4.

Thunderbolt 4 is USB4 Version 2.0

Thunderbolt has additional quality testing as thunderbolt is a trademark that will be enforced and companies will be sued if they try to pass inferior products as meeting the specs.

Thunderbolt is much more than just "USB with all the options enabled".

Thunderbolt lets you "tunnel" raw PCIe traffic over the cable, along with native DisplayPort and USB traffic. It's the raw PCIe traffic that allows Thunderbolt to be used with external GPUs, and (at least in theory) any other PCIe device you want to plug into an external enclosure (disk controller, sound controller, etc).

[You-]

Thunderbolt is much more than just "USB with all the options enabled".

Thunderbolt lets you "tunnel" raw PCIe traffic over the cable, along with native DisplayPort and USB traffic. It's the raw PCIe traffic that allows Thunderbolt to be used with external GPUs, and (at least in theory) any other PCIe device you want to plug into an external enclosure (disk controller, sound controller, etc).

Have a look at page 6: https://www.usb.org/sites/default/fi...20Overview.pdf - usb4 "Tunnels USB3, PCIe and DP protocols".

As i said, thunderbolt came first. But it is part of USB4 now. Its benefits are in certification - a certified thunderbolt 4 product meets all the USB4 v2 requirements, but a USB cable while with the same connection does not need to meet (or advertise) all those specs.