How many ghz needed?

[Flyby]

Just a question about ghz: how many ghz is (generally) helpful for CoD? IIRC the recommended ghz in the system specs is something like 2.66(?). I see some guys running well over 4ghz (quads mostly), and wonder what the return is in terms of FPS gains, or smooth gameplay. I've got this old i7-920 (DO stepping) laying about and am wondering how much juice it will need to run CoD smoothly. As am aside, as a frequent visitor to [Hard] OCP, I see that site setting it's 920 to 3.6ghz " to remove the CPU bottleneck" when testing GPUs. I always figure our combat flight sims probably strain the CPU and GPU a bit more than the average pc games that site tests. Just my opinion.
Flyby out