All the gtx 260s, 280s, and 275s that I have had, squeal while folding and also during extremely high fps, like when 3dmark06 is loading the next test. I got a new hx750 psu, and the noise is gone from the card now. I swapped the exact same card between my 2 systems, with same result. The card that uses the hx750 is quiet, the card using the corsair hx 620 or corsair tx 650 squeals. Just some real world experience....