Ok experimented with affinity. Oddly enough it does not change the hashrate of AMD cards. It did however, drop my Nvidia's from 130MH or so to 6MH when I set affinity to one core. No idea why.
Not skimping on the PSU for sure as you said. No you're right that cheapest is not the best. I feel I've just been as efficient for MH/$ that I could be. Of course I could be more efficient as well. Thanks.
Are you using cudaminer with your 580?
I have a 570 mining with cudaminer (GUIminer) at 125 MH/s downclocked to 732 MHz. It's an OCd version @ 810 MHz (stock clock) reaches 140 MH/s.
The directory shows: guiminer\miners\puddinpop\rpcminer-cuda.exe so I presume that's what you mean, yeah. Currently this second at 132 MH/sec @ 825 core.