We are still just getting our toes dipped in the waters of PCIe 4.0 thanks to AMD's recent launch of the X570 chipset, and Ryzen 3000 series processors -- but PCIe 5.0 and PCIe 6.0 are also on the way. You know the story, technology never slows down.
PCI-SIG has officially announced version 0.5 of the new PCIe 6.0 standard -- yeah PCIe 6.0, not PCIe 5.0 -- which will have an insane 8x the bandwidth of PCIe 3.0 that most people are using today. PCIe 3.0 starts things off with 32GB/sec of bandwidth on a full PCIe 3.0 x16 port, while PCIe 4.0 x16 offers up to 64GB/sec.
Things start to really ramp up with PCIe 5.0 x16 with a huge 128GB/sec, but PCIe 6.0 takes things to the stars with 256GB/sec on a PCIe 6.0 x16 port. This means we're looking at a huge 8Gbps per lane of bandwidth with PCIe 6.0 -- crazy stuff, and while graphics cards won't benefit too much from it (unless things change in a big way), next-gen NVMe SSDs, networking controllers, and other technologies will suck up all that additional bandwidth easily.
PCIe 6.0 will be fully backwards compatible with "all previous spec generations", says PCI-SIG Board Chair and President Al Yanes. He writes: "Two of the key changes that we're implementing include PAM-4 (Pulse Amplitude Modulation with 4 levels) encoding and low-latency Forward Error Correction (FEC) with additional mechanisms to improve bandwidth efficiency".
