When using the default settings without any sort of .ini file tweaks, Wolfenstein doesn't require much hardware horsepower. For this test, we disabled the frame rate limit, as we'd otherwise flatline at 60 FPS. With two cores, the game feels really natural, and the graphics card is fully utilized. Judging by frame rate values, you can even manage with a single-core CPU.
If you have a weak graphics card, you should upgrade it and then go for a dual-core CPU. Graphics memory utilization is minimal, at just 379 MB due to the lack of AA.