PCI-SIG confirms PCIe 7.0 specs are on track to be finalized in 2025
PCIe 7.0 specs draft 0.5, Source: PCI-SIG
While the storage industry has already widely adopted PCIe Gen5, the development of GPUs utilizing this standard has been sluggish. As of now, major players like AMD, NVIDIA, and Intel have yet to release PCIe Gen5 graphics cards. Nonetheless, the progress in the next-generation interface development is on track, and it is already progressing towards 7.0 version.
The PCI-SIG, responsible for PCI Express specifications, has announced that the PCIe Gen7.0 specs are now available in version 0.5. This follows the release of version 0.3 in June 2023. The initiative for this new standard was set in motion back in June 2022.
PCIe Gen7.0 boasts a raw bit transfer speed of 128 GT/s and a bandwidth of 512 GB/s for bi-directional interfaces through a 16-lane configuration. It employs PAM4 signaling and focuses on enhancing power efficiency. A crucial aspect of PCIe Gen7.0 is its backward compatibility with all previous generation PCIe specifications. This means Gen7 GPUs or storage can be utilized on platforms as old as PCIe 1.0 ((but that doesn’t mean anyone should use it).
PCIe Gen7 Goals
- Delivering 128 GT/s raw bit rate and up to 512 GB/s bi-directionally via x16 configuration
- Utilizing PAM4 (Pulse Amplitude Modulation with 4 levels) signaling
- Focusing on the channel parameters and reach
- Continuing to deliver low-latency and high-reliability targets
- Improving power efficiency
- Maintaining backwards compatibility with all previous generations of PCIe technology
PCIe bandwidth, Source: PCI-SIG
Currently, the focus in the GPU market is on PCIe Gen5 adoption for consumers. Although solutions like the Chinese Moore Threads MTT S80 and data-center GPU/accelerators such as Hooper or Blackwell are based on Gen5 specs. Gaming-focused reviews comparing various PCIe specifications indicate that while bandwidth doubles with each generation, the gains for consumer GPUs are negligible.
The decline in consumer CrossFire/SLI multi-GPU solutions has for sure reduced the demand for high-bandwidth interfaces. Moreover, the emergence of new technologies such as Work Graphs will shift more workload to the GPU, reducing the need for extensive communication with CPUs.
Source: PCI-SIG