Originally Posted by
John P. Myers
#1, yes. Each 690 is listed as using a maximum of 300W, so if you've got your 690s all drawing the max, that leaves 300W for the rest of computer which is easily doable since everything other than the GPUs will probably only use 125-175W at the most.
***Note: the EVGA SuperNova wattage is the continuous rating, not the peak which other manufacturers use, meaning there's a bit more headroom with it than, say, a Corsair PSU.
As for #2, yes. If the computer is the only thing on the circuit, 20A is fine, which is what it probably is in your fuse box anyway. If not, you can get a 25A or 30A from home depot for like $10. No worries.