1280x720, low-medium settings, you might average 25fps on some of the console-port games.
Borderlands 2, for example, is playable for the most part on an HD4000.
BF3 multiplayer is not
Starcraft II and Team-Fortress 2 almost run smoothly (ie, always above 30fps)
Skyrim runs surprisingly well on minimum detail (30-40fps)
Lower your expectations and you'll be pleasantly surprised with how much it can actually handle;
If you go in expecting minimum detail + lowest res = 20fps you will find that many games run much better than this - You can either raise the resolution or enjoy smoother framerates. Hell, sometimes even both at the same time!
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