Q3 is a dual-threaded application.
According to John Carmack:
All OpenGL calls (the renderer) occur in one thread and EVERYTHING else (sound, network, AI, physics, input) occur in another thread.
Q3 SMP mode often helps your WORST case framerate (heavy firefights), but usually lowers your BEST case scores due to overhead in the SMP implementation.
Carmack did quite a bit of investigating different methods and combinations of threading for Q3 and came to the conclusion that is just wasn't worth the effort. So, he cut Q3 into 2 threads, gave us the ability to turn that off (back to 1 thread), and called it good.
You CAN turn on Q3 SMP-support without actually having an SMP compliant system. It will give you reduced performance, due to overhead, but it will work. Only really useful for benchmarking the overhead that multi-threading injects into Q3.
Your Video card drivers have nothing to do with SMP support in Q3.
Hope that helps.
Rory
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