The big benefit you get from a dual processor system is when you are running two high-load programs at the same time. E.g.
- compiling a C++ program
- working in VMWare
- Trying out our program
- working in VB
- working in an image processing program
- playing a game
So while I'm compiling a longish project (may take 10 minutes), I have time to play some Warcraft 3 and neither of them is slowed down.
AFAIK none of the compilers is multithreaded, but some make programs are. For example, recompiling the Linux kernel on a dual machine is roughly twice as fast as on a single processor machine. I'm not sure whether MS's nmake can also take advantage of dual CPUs, but my guess is yes.
[Edit: Hum, I didn't find anything related to multiple compiler invocations in the nmake reference, so maybe it's not possible :/ ]
