I have decided to develop a 3D game, and I need a new PC with recent hardware to use as my "baseline" for performance and compatibility profiling/testing.
Now, I would like to test it on both a recent NVidia and ATI (now AMD) graphic cards, but I would hate to have to buy two different PCs just for that. Intel/AMD compatibility is a non-issue nowadays, but you can't assume program-once-run-everywhere when it comes to 3D. I gathered that PhysX in NVidia will be disabled, but since it's NVidia-specific, and I can only have enough time to use cross-platform APIs (like OpenGL), I'm not really affected by that.
So, to restate my question: Is their any major issues (apart from PhysX) when using a NVidia and an ATI graphic cards in the same (most likely Windows 7 x64 + Linux dual-boot) PC? Will the drivers "break" each other, or cause some major performance penalty?
I would prefer answers from someone who actually done this, instead of just pure speculation base on some article, although a reference to a recent article would also be useful.