You want to get Rightmark Memory Analyzer, SiSandra 2007, or Everest.
Here are some goodies for you. They have a cool CPU physics bench.
You want to run you RAM at 1:1 as high as it will go, until you reach a point that it's holding back the CPU. At this point you need to run through some math and bandwidth benches (as well as games for FPS) to see if there is a diminished return on increases CPU frequency in relation to increased memory frequency.
I. E. let's say your memory maxes out at 1000 MHz at certain timings. If you CPU can go higher (you know because you found your max by setting the divider really low), then you can try setting the divider lower. Load CPU-Z and see what the numerical value is of the divider. You can then calculate what your memory is without having to boot and see.
Eventually you will arrive at a trade off between CPU being an extra 50-100 MHz with the RAM being on a larger divider and losing 25-50MHz, or the other way around. It also depends on your motherboards BIOS options.
Another thing you can look into is this cooler:
This way you can crank up the voltage past what you previously have. It really does help in a MASSIVE way.