How does a Xeon compare with a Pentium 4?
 

I currently have a P4 3.4GHz server (which reports hyperthreading but I don't think I've enabled it in the kernel), and I'm looking at a dual Xeon HT 3.2GHz.

How does the dual Xeon HT compare with a single P4 - is this much of an upgrade? (Obviously, there's the benefit of two CPUs, and four logical ones with hyperthreading enabled)

Thanks for any tips