Worst case scenario will be for a passive 8600GT - which will cost about the same.
I have been trying to get my PC as quiet as possible which has resulted in having all my fans at 5v (2 case and 2 CPU HS 120mm and 1 92mm). This has shown my graphics card to be quite loud in comparison, even at 25% fan speed in Rivatuner. The stock fan also appears to get stuck at default speeds (pretty loud) on warm boots.