PCIe 7.0 remains on schedule for future graphics cards and SSDs
And it promises extreme speeds
PCIe 5.0 components for PCs may have only recently come to the fore, but there are already plans for the bus’s successor. No, just for PCIe 6.0, but also for PCIe 7.0 !
Specifically, in the context of this year’s PCI-SIG Developers Conference 2023, the standards committee responsible for the extremely popular PCIe announced that version 0.3 of PCIe 7.0 is now ready , which it is expected to deliver to its partners in 2025, at a rate data transmission up to 128 GT/s.
Of course, although PCI-SIG is already working on various drafts, the first consumer products to take advantage of PCIe 7.0, such as next-generation graphics cards and the next lightning-fast SSDs, won’t hit store shelves until 2027, in best case.
This was a timeframe that was also announced at last year’s conference, but the good news is that a year later, PCI-SIG is optimistic that there will be no delays.
For now, however, we know a few important technical details. In particular, the new version of the interface will provide twice the bandwidth compared to the previous generation PCIe 6.0. According to PCI-SIG, it will allow 512 GB/s bi-directional throughput over an x16 link, but without considering the encoding overhead and the performance impact of the header, which will surely reduce the actual bandwidth.
At the same time, PCIe 7.0 will continue to use the 1b/1b flit mode encoding and PAM4 signaling technology that PCIe 6.0 brought. This is a very significant improvement in both aspects, compared to the technologies used by the version 3.0 to 5.0 specifications.
Another important benefit of the much higher bandwidth per lane is the possibility that many devices can now operate occupying fewer lanes. For example, some cards may be satisfied with a x4 connection, while previous PCIe versions required x8. This can potentially translate to systems being able to support more attached drives and other hardware.
Below you can see a detailed table showing the speeds that can be achieved with from one to sixteen lanes, depending on the PCIe version used.
Unfortunately, all this speed also comes with a downside for consumers. As we saw with the jump to PCIe 4.0 and PCIe 5.0, the length of PCIe circuits will again decrease due to faster signaling rates. This means that the minimum allowed distance (without any additional element in between) of a root PCIe device, such as a CPU, and the end device, such as a GPU, should be reduced. As a result, motherboards will need more retimers and thicker PCBs made of higher quality materials than those needed for current versions of the interface. So, the support of PCIe 7.0 is expected to lead to an increase in motherboard prices.
Of course, the new version will be fully backwards compatible. This means that all motherboards with such ports will be able to work without any problems with products that have older generation PCIe technology.
