A few additional notes from my experience:
After trying too many different PSUs, I recommend Corsair RM550 per S1: modular, so no extra wires around, super quiet, stays cool, ~90% efficiency. I have several pairs running on Corsair RM850 but they get noticeably hot. Buying anything larger than 850 for a pair of S1s to keep the PSUs cool is not cost effective compared to two 550 units.
As for the power draw, according to my kill-o-watt 360W@350MHz, 400W@375MHz with gold PSUs
As for cooling, I tried many different fans/combos and I like this one the most:
- front fan (push) SilverStone FM121 ($20)
- back fan (pull) Cougar Vortex CF-V12HPB ($10)
This setup is super quiet when FM121 is set to midlevel, and has quite a bit of extra pressure/flow for the summer. I live in Texas, so the summer is already getting here
If anybody knows of a quiet (<40dBa) 120mm fan with high static pressure (>=3mm), PWM and at least 100CFM, I would be curious to try that.
Cheers,
Andrew