On the physics vs graphics discussion, if your game has a competitive aspect 60MHz is probably too low for graphics.
Physics and rendering should be decoupled. The simulation's update rate can be quite low in many games. You want it fast enough that players can feel like they are moving freely, but slow enough that all computers can keep up.
The popular update rates have their sources. 60Hz is popular in games because of television standards. Console games and systems come from the standard definition TV era. PAL offers 625 lines @ 50 Hz, NTSC offers 525 lines @ 60 Hz. Since both are interlaced you can get away with half speeds without gamers complaining too much. Modern video standards for HDTV also tend to focus on resolutions at 60 Hz, although many screens and resolutions can go much faster.
That gives the common graphics speeds of 15Hz, 25Hz, 30Hz, 50Hz, and 60Hz.
In competitive gaming and twich-style games, players want all the graphics speed they can get. While it is true a DVI cable's highest resolutions are meant for a 60Hz screen, it can go much higher. 1280x1024 @ 85 Hz or 1280x960 @ 85 Hz are a common setting in the competitive world, which saturates a single DVI cable. Many competitive players buy dual-link DVI monitors that run at 120 Hz or faster, crank up video card speed, and turn down visual quality of everything in favor of speed. The extra images help them aim more quickly and accurately, improving their competitive abilities.
So even if your game physics run at a specific fixed time step (which is common) it should be decoupled from game rendering, which should generally be configurable to run as fast as the hardware allows.
Edited by frob, 03 March 2014 - 01:59 PM.