Doubles the bandwidth each time. https://www.bit-tech.net/news/hardware/2017/06/09/pcie-4-launched-pcie-5-announced/1
They (AMD/intel/etc.) already have trouble filling the current iteration with bandwidth it seems, not sure they aren't moving a bit fast here.
More important for enterprise/servers - although at the other end, small form factors - this means smaller devices with smaller connectors.
I'm wondering if the future is moving towards having the SSDs on PCI-E lanes if they don't need to stuff a few more PCI-E lanes into the CPU/Mobo. That way it can handle all the bandwith that will be required with multiple fast drives and a Vid, or multiple, card(s) on it ......
