Hardware

It's more likely MS didn't think taking a whole bunch Geona systems out of use elsewhere would be worth it. The backlog for Genoa throughout most of h1 made them nearly as unobtainable as H100s.

Most of the CPU time in these sort of systems is usually taken up by relatively basic PCIe traffic management. More likely, SPR and Geona are basically interchangeable as far as this is concerned and SPR Xeon just had less opportunity cost.

If there was actually any special sauce that made a tangible difference with this type of setup, there would be an epic bumrush by everyone to buy up SPR Xeons to host all their H100s, but they're clearly not. Nvidia would have also made a far bigger and more public stink over Intel's failure to deliver SPR on time, due to DGX-H100.