The noise really isn't that bad. Honestly, I sincerely mean that.
The 480 is a noisy card. However, if we follow the laws of sound from a scientific standpoint then we can see that adding a second card hardly makes anything noisier.
As an example right, let's say you have a 18" subwoofer capable of putting out 138db @ 20hz. If you add another one you add about 5db tops.
That law makes perfect sense to me, as running two cards with the fans on 75% is no louder than my 7970 was at the same fan speed. The reason would be simple, the 7970's fan was twice the size of the 480 fans.
I did shoot a video so I will see about uploading that later
But any one who already owns a 480 simply needs to set their fan to 75% in Afterburner and make their minds up that way. I haven't seen either card go over 83c with the fans at 75%.
Any way, more benchmarks. I ran Crysis @ maximum in DX10 with 4XFSAA. The 480 had a minimum frame rate of 29 FPS and the 7970 was over 40. However, the FPS were low when the benchmark first loaded as the camera goes toward the ground but as soon as that was done the game maintained an average of 75 FPS which is higher than the 73 FPS I got from my 7970. I will hand that round to the 7970 though as Min FPS is the most important, even though within about four seconds the 480 SLI was putting out higher frames.
Onto Metro. Everything on as high as it will go, 4XFSAA or MSAA or whatever it is called.
7970 @ 1125mhz. Noting that Physx is switched off in both sets of benchmarks to make it fair.
480 SLI stock.
480 SLI @ 800mhz
Another round to the 480s.
The 480 is a noisy card. However, if we follow the laws of sound from a scientific standpoint then we can see that adding a second card hardly makes anything noisier.
As an example right, let's say you have a 18" subwoofer capable of putting out 138db @ 20hz. If you add another one you add about 5db tops.
That law makes perfect sense to me, as running two cards with the fans on 75% is no louder than my 7970 was at the same fan speed. The reason would be simple, the 7970's fan was twice the size of the 480 fans.
I did shoot a video so I will see about uploading that later

Any way, more benchmarks. I ran Crysis @ maximum in DX10 with 4XFSAA. The 480 had a minimum frame rate of 29 FPS and the 7970 was over 40. However, the FPS were low when the benchmark first loaded as the camera goes toward the ground but as soon as that was done the game maintained an average of 75 FPS which is higher than the 73 FPS I got from my 7970. I will hand that round to the 7970 though as Min FPS is the most important, even though within about four seconds the 480 SLI was putting out higher frames.
Onto Metro. Everything on as high as it will go, 4XFSAA or MSAA or whatever it is called.
7970 @ 1125mhz. Noting that Physx is switched off in both sets of benchmarks to make it fair.

480 SLI stock.

480 SLI @ 800mhz

Another round to the 480s.