Re: GTX 280 screeching...
I had something like this with my 8800 Ultra...got really annoying. It got worse when I switched to a P5K Deluxe motherboard as I recall. I finally tracked the high pitched noise to the power supply. I replaced my PCP&C 750 watt with another, and same problem..then I switched to the 1kw enermax and end of problem.
I7 950 processor/Ultra 120 Extreme cooling/Asus P6T Deluxe V2 motherboard/6Gb corsair 1600C7 ram
Evga 280 FTW video/Mitsubishi 2070SB 22" monitor/SB XFi-Titanium sound
Enermax Galaxy DXX 1000w Power Supply/Coolermaster RC-832 case