I put one of these on my Asus 9500gt, which had started out quiet enough, but got  steadily more whirry with age.  I think all small fans on VGA cards do this.  Anyway, fitted this as per Zalman instructions, turned the fan down to lowest setting, and its great.  Knocked out any of that buzz.  Temps are about 31 degrees idle, better than early forties with the stock cooler.  I guess next test will be turning the fan off all together, which I think it would manage.  Cost $80 though, but there are no fanless 9500GT's to be had.

http://www.testseek.com/labs/reviews/review-of-the-zalman-vf2000-led-hybrid-vgacpu-cooler/?p=704

Ivan