I've played about 40 multiplayer games so far and about 20 in the campaign (though I'm only on mission 6... playing on brutal)... it runs fine, sometimes is a tiny bit slow at first in a campaign mission for about 5 seconds but then smooth as butter. My "recommended" requirements were basically all maxed out even though I hardly have a super computer. But anyways, one game I get a message that pops up and says something along the lines of "your computer has run out of video memory, graphics settings have been reduced but gameplay may still be affected". Wish I'd written it down but didn't think too. Anyways 5 seconds later the game turns into a slideshow for both me and my opponent so I surrender and quit. I'm not overclocking either, actually I'm slightly underclocking (not by much just a little). What does this mean? I have a 4650 which I know isn't a super awesome card but it's well above the minimum reqs, and like I said, the game runs smooth as butter. No FPS issues whatsoever except for that one time after I got the message. Also as a sidenote. How the hell do I register on the Blizzard forums? I get this when I try to access the SC2 forums: An error was encountered while processing your request [Forum not found] Then I tried the battle.net forums but I can't figure out how the hell to register/login. It asks me what "realm" I'm in (this is in the top right), which is a WoW thing afaik, so I select East USA (where I am), enter my email (which is what SC2 uses to login) and enter my cd key correctly and it won't login.
I think you have to try the new Battle.net forums which are on starcraft2.com not Battle.net. You have to go to the community site then click "forums." Or click this link http://us.battle.net/sc2/en/forum/ Anyway as far as your video card. It sounds to me like it was a one-time glitch with your video drivers. Card must've freaked out for any number of reasons and given you the error. I wouldn't really worry about it but you could also try upgrading your video drivers to the absolute latest. Or run you game in administrator mode, that helps a lot of issues. Good luck!