Hello, i would like to know why some games cant run at at a LCD's native resolution.

Graphics card is 8800 GTS 320.

EG. on a 19inch widescreen with native resolution of 1400x900, HL2 EP2 runs at only 1280x1024 max.

on a 19inch normal screen, with native resolution of 1280x1024, Prince of Persia WW runs at only 1280x900 MAX.

i am planning on buying a 24inch screen which has a resolution of 1650x1080 but whats the point if a game doesnt use full res? is is because games like HL2 EP2 is capped at 1280x1024?