Re: GTX 280 screeching...
I just upgraded to the Silverstone Zeus 1200w, and the screeching has gone away. I don't know why exactly, I'd assume it would be the quality of the components involved, as the Zeus is a advertised as a "workstation" grade power supply, unlike my old Silverstone Strider 850w which was simply labeled "silent". I don't think it's a rail issue, this new PSU has the ability to switch between multi and single rail configurations, but currently I'm still on multi-rail with 6x16A.
__________________Core i7 980x @ 4.4GHz - EK Supreme HF - BlackIce GTX 360 - MCP655 - Rampage II Extreme BIOS 1639 - EVGA GTX 480 SLI - Corsair Dominator 3x2GB DDR3 1600
2 x 1TB Samsung F1 RAID 0 - Plextor PX-880SA DVD Burner - Dell 3008WFP - Silverstone Zeus 1200w PSU - Lian Li PC-P80 - Razer Mamba - Logitech G15 v2
Windows 7 x64, 3DMark06:30000, 3DMark Vantage: P38000
Eurocom M860TU: X9100 - 9800M GT - 2x2GB OCZ DDR3 1333 - 320GB 7200rpm - 15.4in 1920x1200