Get Ready: PCIe 7.0 Will Be Insanely Fast at 512GB/s

The PCI Special Interest Group (SIG) announced it's moving ahead with the PCIe 7.0 spec, which promises quadruple the bandwidth of the most cutting technology we have today in PCIe 5.0. The group announced its progress at its annual conference in Santa Clara this week, stating that version 0.3 of PCIe 7.0 was now available to its members. This will allow companies to get a head start on future products supporting the standard, which is supposed to be finalized in 2025. After that, it's predicted PCIe 7.0 devices will begin to arrive around 2027.

The group first discussed PCIe 7.0 last year, just as PCIe 5.0 began to roll out to customers with Intel's Alder Lake platform. Its newest announcement nails down a few of the details of the nascent technology, confirming its members have agreed on the initial specifications. It's still targeting 512GB/s of bidirectional bandwidth, which doesn't account for overhead. Therefore, the actual final bandwidth number will be a bit lower. That's still four times the current 5.0 standard, 128GB/s on an x16 connection. PCIe 6.0 will theoretically double that to 256GB/s, as is the standard for PCI Express connections, which double with every iteration. In general, the amount of bandwidth offered by each successive PCI Express standard is designed to double every three years.

This chart shows the upcoming increases in bandwidth afforded by the adoption of upcoming standards. Credit: PCI-SIG

Since version 0.3 is still in the early stages of development, the announcement from the group is somewhat light on details. However, it does confirm the bandwidth targets and the use of Pulse Amplitude Modulation 4-level (PAM4), along with what it calls "defining the channel parameters." PCIe 5.0 uses non-return-to-zero modulation, so PAM4 will first be adopted in version 6.0, then used going forward into 7.0, and will allow for double the data rate across the same number of lanes. Even though this technology will eventually arrive in our PCs, the group states it will initially target HPC, cloud and quantum computing, AI and machine learning, and other advanced applications.

The group says with version 0.3 now ratified by the group members, it will continue to work on fleshing out the details in preparation for version 6.0, which was first discussed in 2019. Since PCIe 5.0 is just now beginning to roll out and is still not the default on Intel's Raptor Lake platform, we can expect to see PCI 6.0 devices appear in several years. Intel's Meteor Lake architecture will likely switch to PCIe 5.0, joining AMD in making it the standard, which will increase adoption for both SSDs and memory supporting it.