In a recent blog post PCI SIG has provided an update on their progress in drafting the PCI-Express 6.0 specification. It only completed its PCI-Express 5.0 back towards the end of May, but it has been very quick with outlining the specifications for PCI-Express 6.0. They plan to double the raw bit rate to 64GT/s and have announced that revision 0.3 of the PCIe 6.0 specification is complete and it plans to have the final specification available in 2021.
When most of the information we’ve already known since June, the blog post does say that the technology will “double the data rate to 64GT/s while maintaining backward compatibility with all previous spec generation.” Furthermore, PCIe 6.0 “includes PAM-4 (Pulse Amplitude Modulation with 4 levels) encoding and low-latency Forward Error Correction (FEC) with additional mechanisms to improve bandwidth efficiency,”.
So 64GT/s refers to GigaTransfers per second over the interface. That basically equates to 256GB/s of bandwidth (or 128GB/s in each direction). If you look at the graph above you can see that PCI SIG plans to double the raw bit rate from PCIe 5.0 to PCIe 6.0. They also don’t want there to be a large gap between revisions like we saw from PCIe 3.0 to PCIe 4.0.
Via PCI SIG