I have a gaming machine/audio machine and I'm finally putting down some money for a Mac Pro (as my dedicated DAW) and keeping my PC as a gaming/internet build.

I'm looking for a reliable KVM switch (a switch that allows me to have one monitor display, yet have 2 computers hooked up to it simultaneous so I can switch back and forth but leave them both on).

Why do some display cards look better than others thru a KVM switcher? What "spec" should we look for in a display card when we know we want to use a KVM? ie: My Matrox G450 looks awful at 1280 X 1024 yet my Nvidia GeForce 2 "something or other" looks great. Why?