By frametime are you meaning your frames per second? If so, lot's of things will play a part in what kind of performance you get. Everything from CPU, your graphics card, RAM, what time of day it is (just kidding), what version of windows you have, play a part in the experience you get. Even if you have up to date drivers and everything, you'll still get a good deal of variance in frame rate from game to game depending on how demanding it is.