[Buckeye]

I think what a lot of the big guy or well known names do at times is use two large PSU's so they can provide as clean as power as they can get. One PSU powers the GPU's and the other for the rest.

I don't really know who that effects things, just something I have seen.

I have often wondered how pieces of equipment handle two different power sources and if they mix well with out any problems.

Example...

A GPU has power coming from PSU #2 through the main power connectors.
It also gets power and signals through the PCIe expansion slot from PSU #1.
How that effects ground and signals I don't really know.