Although AMD has already implemented PCIe 4.0 across a range of mainstream products with its Ryzen 3000-series processors and latest graphics cards, Intel is still stuck on PCIe 3.0, having canceled its plans for PCIe 4.0 on Comet Lake. Meanwhile, PCI-SIG, which makes the PCIe specifications, announced version 0.5 of the upcoming PCIe 6.0 spec today, which features eight times the bandwidth of PCIe 3.0.
Even though we've yet to see products supporting PCIe 5.0, PCI-SIG first announced it'd be introducing a PCIe 6.0 spec in October. The spec's jump in bandwidth is no surprise, as each new generation of PCIe doubles the bandwidth of the previous. Where PCIe 3.0 has a bandwidth of 8 GTps per lane, PCIe 4.0 doubles that figure to 16 GTps, and PCIe 5.0 jumps to 32 GTps. Logically, PCIe 6.0 makes the jump to an impressive 64 GTps per lane.
Those figures translate to about 8 GBps per lane of PCIe 6.0, which for a 16-lane slot would equate to nearly 128 GBps per slot. Consequently, it wouldn't come as a surprise if the eventual arrival of PCIe 6.0 devices meant the days of full-length PCIe slots were numbered. The first sign of this was AMD's Radeon RX 5500 XT graphics card, which only needs 8 lanes thanks to PCIe 4.0 support.
These figures are achieved by encoding with Pulse Amplitude Modulation with 4 levels (PAM-4). The specification also features low-latency Forward Error Correction (FEC) and will be compatible with all previous versions of PCIe.
According to PCI-SIG. the PCIe 6.0 spec is on track for delivery in 2021. That doesn't mean we'll be seeing products with it in 2021 though; it only means that hardware vendors will start developing supporting products.
The biggest areas that will benefit from faster PCIe, at least initially, are high-computing platforms, such as artificial intelligence and machine learning. It will likely take significantly longer before individual consumers start leveraging the increase in bandwidth.
PCI-SIG will share more details at its upcoming Developers Conference on June 3 and 4.