"The game tic simulation, including player movement, runs at 60hz, so if it rendered any faster, it would just be rendering identical frames. A fixed tic rate removes issues like Quake 3 had, where some jumps could only be made at certain framerates. In Doom, the same player inputs will produce the same motions, no matter what the framerate is."In a mostly unrelated note, we'd like to thank IGN for doing a story today on DOOM 3 and NVIDIA (who prefer their name be shown that way in print) to help celebrate INTRNATIONAL CAPS LOCK DAY.