From MacWorld : Charts The COD4 test was a shame for the 13", 38.9 fps for the low-end 13"against 68.4 fps for the low end 15". "Comparing the new 13-inch MacBook Pros to their 15-inch siblings, you can really see the performance difference that the Core i5 and i7 processors and the discrete graphics can make. The 15-inch 2.4GHz Core i5 model was 16 percent faster overall than the 13-inch 2.66GHz Core 2 Duo MacBook Pro. The Call of Duty test showed the GeForce GT 330M graphics in the 15-inch model could display 75 percent more frames per second than the fastest 13-inch model. Cinebench was 24 percent faster, Aperture was 32 percent faster, and Photoshop was 10 percent faster in our tests."