Comment by ajb

Well, it's not my field, but pci5.0 x4 drives are the fastest I found with a quick Google. So 24 of those would top out at ~400 GB/s. That's also where HBF starts out, for one device. The higher grades are faster, but maybe NVMe will be as fast by the time they are out.

But the win here on servers is almost certainly power. High speed signals are power hungry, and the power scales with the length of the wire. HBF is designed to go in the same package as the GPU, so the distance is much shorter than with discrete drives.