Overclocking RAM for simulation and compliation

Main memory accesses are so much slower than cache accesses that increasing the cache size (or decreasing the size of the working set) is likely to have a greater effect than minor changes in memory speed.

Memory with a higher clock speed often requires more clocks before the data is returned - so the speedup isn't as great as you might imagine.

Clearly running the whole system in a bath of liquid nitrogen so that the clock speed can be increased by 50% will make things significantly faster!

You might also find that compilation/synthesis is unable to keep all 8 (with hyperthreading) cpu cores busy. Since the busy thread keeps changing the OS may well schedule them of different cores - and then reduce the cpu clock frequency because the cores are idle!

So look at the power (safe) settings - they may well have a larger effect that the DRAM clock speed.