Current SSDs, but there is literally nothing stopping people from putting PCIe switches in place and maxing out literally any PCIe link you can create. The lim

Current SSDs, but there is literally nothing stopping people from putting PCIe switches in place and maxing out literally any PCIe link you can create. The limit then becomes the amount of RAM (or LLC cache if you can keep it there) bandwidth in the machine unless one is doing PCIe PtP. There are plenty of applications where a large part of the work is simply moving data between a storage device and a network card. But, returning to PtP, PCIe has been used for accelerator fabric for a few years now, so a pile of GPGPU's all talking to each other can also swamp any bandwidth limits put in place between them for certain applications. Put the three together and you can see what is driving ever higher PCIe bandwidth requirements after PCIe was stuck at 3.0 for ~10 years.