Hello,
I'm almost sure that even an high-end cpu won't make a big difference. When it comes to compiling, most of the time is taken by disk IO. Here are a few tips :
1) If your llblgen projects take a long time to compile, put them in a new solution so they won't get recompiled unnecessarily over and over.
2) Buy fast, high end disks like WDRaptors.
3) If your computer has got enough memory ( > 3gb), consider working on a Ram disk. (check Mihies's blog for a piece of advice). In my case, it has proved to be the best solution.