If you go with recommended PSU's it is required. The PSU's they recommend don't work with 120.
But yes you could keep throwing 120 lines to lower power PSU's. But would not make a lot of sense. Just look at amount of PCI-e cables it takes. But if you ROI'ed on a lot of ATX supplies and had multiple line's of 120 close together yes you could run it.
But yes you could keep throwing 120 lines to lower power PSU's. But would not make a lot of sense. Just look at amount of PCI-e cables it takes. But if you ROI'ed on a lot of ATX supplies and had multiple line's of 120 close together yes you could run it.
They "recommend" their own PSU and it has nothing to do with what is optimal, only what is profitable
120V PSU's are no less effective at powering this beast, so long as each PSU has enough rating to fully power each board fully (only 1 PSU per board), but 12V is 12V. 240V PSU's gain a couple percentage points in efficiency, and when you get into the larger server PSU's they require 240V, but the hardware could care less what's feeding it.
The amount of PCIe cables it takes to run would not change whether you had 9 individual PSU's or 1 4000W PSU, not sure what relevance that has to PSU selection? The best PSU for the job is either the one you've already paid for, or the one that will do the job for the least amount of money that meets your expectations (efficiency, etc) without dying.
