What is the benefit, precisely, of...

[Leon]

dual processors on a PC? Is it simply a speed thing?

[Martin T]

better when you're running lots of programs at once, like a server. For a desktop, its pointless. Some workstations use dual processors (or more) if they use software that supports 2 or more processors.

[Dave_S]

You will first of all need an O/S that supports multi processors, WinNT 2k/XP/Linux comes to mind.

Some applications can then use multi-threading to utilise both processors at once. To be honest, for the average joe this is a waste of money / tech. Quake 3 will support SMP (Synchronous Multiple Processing (IIRC)) but it doesn't really make much difference. Better to spend the money on more ram and a new GFX card :)

Dave