When my brother bought his 2 GTX 460's the total came to about $50 less than a single 480. I hadn't realized how much the prices of 480's have dropped since then.It's fairly subjective, they're about 20% faster than a single 480 but with the drawbacks of multi-gpu.
There are drawbacks to SLI or Crossfire, notably driver issues, poor scaling, stuttering, micro-stutter(not to be confused with stuttering), twice the heat, twice the power consumption, cooling issues and more. I use multi-gpu, but don't think a 20% performance increase is worth it to take 460 SLI over a 480. A single 480 would be my preference in that situation.
In Canada I can get a 480 for $450 right now, and a 1GB 460 at the cheapest is maybe $200 and that is from a crappy vendor who RMA will be a PITA with if I have a problem. If I bought 2 EVGA 460s, the cost would be the same as a single 480.
Multi-gpu is great, but from my past experience, is best left to being done on flagship cards. IMO of course
SLI scales better than Crossfire depending on the situation. Which is why 460 SLI can deliver some decent numbers compared to 5870CF, but a single 460 on its own is a good deal slower than a 5870.
I hope AMD can improve their scaling with the upcoming 6 series. So I welcome news like this of them improving multi-gpu scaling. Their only weakness atm in performance from my perspective is Crossfire scaling. If we can get 150+% the performance of 480 SLI out of 6870 CF, that will pretty much be enough horsepower to run any game at its highest settings at my current resolution with a 60fps avg :thumbsup: