Processor Equality?

Question/Problem: In preparation of a new game coming out, I'm trying to upgrade my system to be able to support The Sims 3. I know I need a few upgrades, such as my video card and RAM, but my biggest problem is processor compatibility. Minimum requirements for TS3 is a 2ghz Pentium 4 processor, but I'm equipped with two 2.66ghz Pentium(R) D processors. I can't seem to find any information regarding the equality of these two different processors, or if there even is any equality or difference.

Operating System, Version and Service Pack: Windows XP SP2

Web Browser and Version: Firefox 3.0.8

Your level of experience: Beginner (I'm hardware-stupid)

Any steps you've taken to troubleshoot? Searching to the ends of the internet?