I'm getting higher frame rates in all of my games (COD MW 3, Battlefield 3, Skyrim, etc...) on my new monitor 23" LG 2381VR-BN w/ 1920x1080 resolution than i did with my 19" LG W1942T 1440x900 res... why is that?
PDC E2160 OC'd to 3 ghz (can get it to 3.4 but BSOD's after a few minutes, might be a mobo prob or PSU prob)
asus P5Q p45 mobo
2x2 GB 667 1:1 ratio
2x512 MB 667 1:1 ratio
2x 1TB samsung F3
Palit: nvidia gts 250 512mb (e-green edition... LOL)
astone case with 600w PSU
Did you change any game settings between changing LCD's?
But in reality it might not be as much of a "weird" situation as it might be. The CPU is used much more in lower resolutions (and 1440x900 is pretty low for a desktop), and in higher resolutions, the GPU get's pushed more than the CPU (well it depends on the resolution as well).
Maybe it's just that you have been wowed by a larger, nicer screen