PCI-SIG has finalized the specifications for PCI Express 5.0 that can reach data transfer speeds up to 32 GT/s or 128 GB/s on an x16 bus — twice as fast as PCIe Gen4. PCI Express 5.0 is expected to be available for datacenter and AI applications first followed by HEDT and consumer platforms sometime in 2021.
https://www.notebookcheck.net/Need-for-speed-PCI-SIG-finalizes-PCI-Express-5-0-specification-that-offers-up-to-32-GT-s-transfer-rates.422793.0.html