Real pro's play on the lowest settings anyway, only real noobs play on high gfx settings....
exactly but this is ALSO where CPU speed counts most.. because you're cpu limited at lower gfx settings..
There's a couple of guys that I've seen go around recommending AMD cpus and even early i7s for starcraft 2..
They were all like.. yea I get 150 fps.. they're always looking at the beginning of the game.. and not the middle..
in large battles, sc2 dips to 40-50 fps on my 5ghz 2500k.. and I've seen battlefield 3 situations where I'd get 40s and 50s as well.. with MINIMUM graphics settings.. ..
CPU is king in competitive play... GFX doesn't even matter...
I'd venture to say the cut-off for gfx is an ati 7850.. while for cpu, nothing less than a 4.5ghz 2500k..