GeekBench is a piece of software that allows you to benchmark your system and then compare your benchmark against similar computer systems. GeekBench was created by PrimateLabs and has both a free and paid version of their software – the paid version goes for about $20.
The paid version allows you to run the 64bit version of the application which will allow you to compare 32bit benchmarks to 64bit benchmarks so you can see how your system will handle 32 vs 64 bit applications. However, if you are just looking for a straight up benchmark, the free version will work just fine. GeekBench works on Windows, Mac, Linux, and Solaris.