hey apok, not saying to do this, as your computer is old enough so I don't think the ram can be, but, I think you should look at overclocking your ram (since you're gonna be changing your fsb I'm talking about the timings)
Check the timings and don't mess with the CAS, because you probably can't get that down while raising the fsb, but look at the rest of the timings and maybe try to bring them down just a tad (if your mobo lets you) This usually results in raising your benchmarks a good amount (ratioed to your computer of course).
gl if you're able to mess with that stuff, if you want to anyways...