There will be no problem with the processor, you'll just need a free PCIe slot on the motherboard which i assume you have your current gfx card plugged in, so that should be no problem.
I don't work in mudbox so you might want to check. It works fine in zbrush so... Should be no problem in max.
If you work with vray the card does vray rt just fine in fact i have two of them in one box in SLI and it works great with vray.
I've run the card through Maya, zbrush, marvelous designer, nuke, Mari, aftereffects and i've been pretty pleased especial as it's not a expensive card i'm happy with it.
All the best
Dave
From a readers' Q and A column in TV GUIDE: "If we get involved in a nuclear war, would the electromagnetic pulses from exploding bombs damage my videotapes?"