Duittuit,
I'm running a 750 watt power supply in both Hollywood and Dreamer. I think I could have gone less - I think Kitt runs with less power.
They recommend at least 450 watts on most that I've seen. One of my cards takes an 8-pin power and a 6-pin power connector - they sent an adapter for both, I only needed it for the 8-pin - the one that they sent was junk and caused me issues - so I replaced the power supply and made sure the one that I switched to had that extra 8-pin power line - I probably just could have ordered in a different adapter, but I didn't want to wait for that to come, then find out that I didn't have enough power and have to wait on that - can you believe that Sun is impatient? ;-)
I can't remember if Kitt has a 550 or a 650 watt power supply.
I'm liking what Micro said on that card he's looking at - if I were ordering another one, I'd be looking hard at it. Look at the number of Cuda cores and also look at the Core Clock speed. Most the 660ti's that I see have 1344 Cuda cores - some of the plain 660's have 960 Cuda cores and some have 1344, and some might have something in-between. Clock speeds will affect it as well.
Have I made it clear as mud? ;-)
Sun :-)