Copy pasta although I doubt a card that can beat the 460sli is "cheap".
The GTX 580 will improve your minimum framerates over the GTX 460 SLI setup. This is a key consideration for overall smooth gaming.
"If you are on a budget, and want to get into the NV Surround and/or SLI game, there is no questioning that GeForce GTX 460 1GB SLI is the best value. It provides high framerates and incredible SLI scaling. We are continued to be impressed by GeForce GTX 460 1GB SLI. If you have the money though, a GeForce GTX 580 is going to offer you more and provide a better gameplay experience without the hassle of worrying about SLI being supported in new games."
"What strikes us about our gameplay experiences today is the fact that with GTX 460 1GB SLI the 1GB of RAM on the GTX 460 may be holding it back at higher resolutions with AA. In all of our gameplay testing, we were surprised how well GTX 460 1GB SLI keeps up with the more expensive GeForce GTX 580. While it comes close, and at times exceeds it in framerate, it doesn’t deliver the same gameplay experience. The GeForce GTX 580 has more RAM on board, 1.5GB to be exact, and this seems to be giving it an advantage in some DX11 games when AA is enabled at high levels."
"GeForce GTX 460 1GB SLI offers performance that competes with a single GeForce GTX 580, but ultimately is limited by its 1GB of memory per GPU at high resolutions with AA. The GeForce GTX 580 offers a smoother gameplay experience and higher playable settings. The GeForce GTX 580 may be more expensive, but that price can pay off as we move into new DX11 games pushing the boundaries of graphics card memory capacity. The fact is GeForce GTX 580 offers you more options by allowing you to install a second video card that improves performance even more."
Even a gtx 580 won't be faster, I'm confused as to why you want to down grade. Your going to need to sli/crossfire something else in order to best your setup by a reasonable amount. Or you'll have to shell out the money for a single card like the 590 or 6990.
Hi there, the reason I'm having to, I guess you could say downgrade from SLI is because the 2 GTX 460's are causing heat problems together, the card that sits at the top is hitting 99oC and has crashed out on me a few times (probably hitting the 105 cut-off limit). I could just use 1 GTX 460 but obviously that would have nothing on running the two, so I'm forced to shell out a bit more for a card that can match the frame rate of a 2x 460 SLI setup.
Thanks for the recommendations though, appreciate it.