Quite regularly, announcements on the future of the PCI-Express land. And while PCI-Express 6.0 does not actually exist in our devices yet, information about PCI-Express
Quite regularly, announcements on the future of the PCI-Express land. And while PCI-Express 6.0 does not yet really exist in our devices, information about PCI-Express 7.0 is being distilled in dribs and drabs.
Little quiz, dear reader: will you be able to find the major brand that is not present in this marketing image?
The standard managed by the PCI-SIG (PCI Special Interest Group) will once again double the speeds of a line, to reach 16 GB/s, the same bandwidth as a 16x slot in PCI-Express 3.0. A PCIe 7.0 16x slot would therefore reach 256 GB/s and a 4x slot – for example for an M.2 SSD – could go up to 64 GB/s. As usual with the standard there is backward and forward compatibility, i.e. a PCI-Express 1.1 card from 2005 can work in a 7.0 slot and a 7.0 card will be able to work in a old system, obviously with reduced bandwidth.
The way of transmitting data under the hood is changing.
A matter of dates
The 7.0 standard is currently at the draft level in its 0.3 version, and the final version is not expected before 2025. And as always, once the standard has been validated, we will have to wait for the first cards. PCI-Express 4.0 (used by Apple in its current chips) was validated in 2017 and the first peripherals date from mid-2019, with for example AMD’s Ryzen 3000 processors, released at the same time as the first SSDs. For PCI-Express 5.0, the same thing: a final version in 2019 and the first devices towards the end of 2021.
On this standard, compatible cards are also rare: some motherboards from Intel with 12th and 13th generation CPUs (this is not systematic), AMD Ryzen 7000 in some cases – again, the standard n is not widespread on motherboards — and some SSDs. Modern graphics cards, for example, are still PCI-Express 4.0 in the majority of cases.
One of the current problems, which will obviously be amplified with versions 6.0 and 7.0, comes from the wiring. The high frequencies used pose signal integrity concerns and this is one of the reasons why manufacturers limit themselves to PCI-Express 4.0 on entry-level cards, even if the processor controller supports the standard in version 5.0. PCI-SIG obviously has this concern in mind and therefore also offers precise specifications for internal cabling in servers and other PCs.
In practice, therefore, you probably shouldn’t expect PCI-Express 7.0 before 2027… perhaps in a new generation of Mac Pro.
