It's possible to bypass the CPU in some cases using NVMe over an RDMA layer with Infiniband. PCIe 4.0 dual-port 200Gbps Infiniband/Ethernet adapters exist[1] wh

It's possible to bypass the CPU in some cases using NVMe over an RDMA layer with Infiniband. PCIe 4.0 dual-port 200Gbps Infiniband/Ethernet adapters exist[1] which are compatible with this approach: https://store.mellanox.com/products/mellanox-mcx653106a-hdat-sp-single-pack-connectx-6-vpi-adapter-card-hdr-ib-and-200gbe-dual-port-qsfp56-pcie4-0-x16-tall-bracket.html https://store.mellanox.com/products/mellanox-mcx653106a-hdat... [1]Although you can't saturate both of them through even a 16 lane PCIe 4.0 port which has ~250Gbps of throughput each way.... Which to me means that PCIe 4.0 is not at all too soon.