Hi. something n my computer is buzzing whenever i start any game. I think my GPU is buzzing because ever since i got it, i kept hearing the buzz sound when starting games and i hear it when i run furmark stress testing. could this be the PSU or the graphics card? PSU: Xilence XP500, GPU: Powercolor Radeon HD 6850
well It could be either the PSU or the GPU. I suspect it's the fans.
The Extra load (assuming the power demands are higher from your old card) may be causing your PSU to spin up a bit fast then it normally would and causing vibrations. It could also be the GPU fan. You should try tapping and/or pressing onto your components see if anything changes (Just make sure you only touch the casings and not the circuit boards). my computer buzzes sometimes but it stops when I press onto my PSU (Caused by cables routed behind the PSU). Also check that you haven't got any loose cables pressing against or touching things like fans or the HDD (You could of easily done this while installing the GPU). It can also be caused by loose case slots (Covers for expansion cards and GPUs or even the GPU its self)
I once had a corsair 450 watt psu that my made my gtx 460 squeal. Changed my psu to a seasonic and my card stopped squealing. Funny how I had a hd 4850 paired with it not so long ago and had no problem with squealing.