Incredibly well. Granted, it rarely gets a workout as I tend to use my PC to play the various RTS and RPG's that I love so dearly rather than the eye-candy laden and system abusing cutting edge FPS games. I got over graphics as a selling point a loooooong time ago.
When it eventually starts to struggle, the board is easily capable of handling a more powerful processor, my memory could be doubled for a pittance, my video can be scaled through crossfire for a tiny sum and an entirely new revision of video card is available for a few hundred bucks. Really, the only problem I have is that I tend to leave a lot of memory hungry apps open at once. Just right now, after finishing a few rounds of Dawn of War 2, I noticed that I have firefox open (~300 megs - I have a LOT of tabs open at once), iE (~100 megs - lots of sites I use don't display properly in firefox), Thunderbird (~60 megs - quite a lot for something that just pesters me with e-mail notifications) Eclipse (total of about 1 gig - 200 for the actual program and the rest for the various instances of the Java VM running. Apparantly I didn't kill the various processes it was running before playing) and Folding @ home which happily chews away at a full core of my processor. In total I was using about 30% of my CPU and ~45% of my memory and still played Dawn of War at the highest settings in the largest games without a hitch. And, the actual computing hardware only cost me 900 USD. More than a year ago.