I'd just like to post my experiences with a GTX 260.
My findings exactly match the results that
WR304 has gotten. I had an EVGA card, non overclocked, same voltages. Stock fan speed is 40% which was 1350rpm for me. At this level it's certainly not quiet. I think my system is pretty decent in terms of noise.... noise sources are 2 800rpm S-Flex's, the 'louder' WD3200AAKS, and a NeoHE 500W. You can clearly hear the GTX's fan over everything else. At 30%, I'd call the fan quiet. It was still noticible in my system, but only slightly. This is the maximum that I'd say is quiet. The lowest setting was 25% which blended into my system nicely. But then the card has temperature issues.... The GTX idled at 61C. I'm sure that's perfectly acceptable, but that's pretty hot to me.
But I had other issues too. For some reason my system crashed under any 3D load. Naturally, you'd think it'd be drivers or temps.... both were ok. Then you'd think its a power/current issue. My 500W NeoHE has 3 17A 12v rails. 450W cobined.... I'm 100% certain that's enough power/current. I made a
thread at EVGA and the
voltage of the 12v rail became a possible issue. I measured 11.95v under 100% CPU load. Still, the card crashed whenever it got up to its full clocks.
BUT, I don't fault the card for these issues. I'm leaning on saying its a PSU issue, but I can't say for sure. Either way, I don't have enough money for a new PSU. Not just that, but you'd
think that a 500W PSU with 90% of its power on the 12v rails would be able to power any single graphics card.... The fact that it was noisy, had no aftermarket cooling support ($50 for HR-03 is too much), and it didn't work in my system was enough for me to give it back.
So I began looking for alternatives. Preferably something you could cool passively with a S1. Literally a few days later, Tom's posted
this godsend article. 4830 Crossfire. Perfect. The setup would
outperform a GTX 260 and since the heat was spread across two GPUs, they could be easier cooled. Plus the setup cost only $30 more, which included the second S1 I'd be needing.
So in sum,
I found the GTX 260 to be too loud and difficult to cool. YMMV.