CPU benchmark advice

Say, any of you Robocoders have a fast quad-core machine (like Core i5/i7 or comparable) and feel like advising me? I'm considering buying a Core i7 (2600k) quad-core box that would mainly (for now) be for Robocode. But I'm wondering how much of a speed increase this will offer me.

• How long does a minimized 35-round battle of Diamond vs itself take? (Maybe run one then "Restart", if that helps JIT things up...) I'd need to know the Diamond version, Robocode version, and what CPU you've got to make full sense of that info.
• How much of a speed hit do you take per battle when running 4-threaded RoboResearch? Ie, if a given battle takes 60 seconds when you run single threaded, does it still take 60 seconds when you run 4 Robocodes, or how much of a hit does it take?

This would be a huge, geeky indulgence, so I'd love to get some idea what I'd be getting for my money if I actually pull the trigger. =) Thanks!