How do I benchmarked games?

I just recently bought a 7600GT (I feel like a dick for not buying a 7900GS; I want some newnew shit for once) and I also have set up Windows XP/Vista dual boot.  Now I had previously been using Vista as my only OS, but after deciding to start gaming, I figured XP would be faster.  But is it really?  If so, to what extent?  I've read older benchmarks that say XP is the winner, but now that Vista has gone gold and nVidia keeps updating their drivers, I want to see for myself.  I actually prefer to use Vista over XP for a few reasons, but don't want to lose 10FPS on that shit.  If it turns out Vista is just as good, better, or not all that much worse, then I will go back to using it all the time.  If not, I guess I will stick to XP until hardware/software makes it irrelevant.

So far I've only played FEAR on either OS.  I don't visually see that much of a difference, but my eyes could be fooling me.  Anyway, I have no idea how to benchmark stuff.  I googled and couldn't find shit.  So can someone help me out?

In before "Vista sucks".

>>10
That's like saying, "enjoy having to type in a serial number, retard".

Everything is cracked.  No one cares about security measures.