I ran several games at high settings 720p on my HD 4400 before I got my GTX 750 Ti. The resolution is the big thing when using an integrated chipset; 1280x720 is ideal for optimization, 1366x768 is still good, 1600x900 is possible in low-spec games (like World At War or The Killing Floor) but harder, and 1920x1080 won't run much at all above minimum.
I ran several games at high settings 720p on my HD 4400 before I got my GTX 750 Ti. The resolution is the big thing when using an integrated chipset; 1280x720 is ideal for optimization, 1366x768 is still good, 1600x900 is possible in low-spec games (like World At War or The Killing Floor) but harder, and 1920x1080 won't run much at all above minimum.