Catamount, on 30 April 2012 - 07:10 AM, said:
If you're referring to the 690, then good luck with that, since it's physically impossible to use more than two

Three 690s would be a total of six GPUs, and graphics drivers are not designed to take advantage of more than four. Even then, the third and fourth give absolutely abysmal performance returns, more often than not.
But for some reason they do reduce microstuttering apparently, so if you're spending an extra $1000 to remove microstuttering, go all for it.