Vray System parameters regarding computer system.

I would like to know if there is a method to have the best ratio between:

-ram, CPU power/render region division.
-dynamic memory limit/ram CPU power

All these when IRMAP/LC/DMC img sampler

In exemple my own config on W7:
2 xeon X5680 @ 3.33Ghz
48 Go RAM

I’m searching to use a maximum of ram to decrease render time.

THX a lot by advance for your answer.
regards.

Laurent

i know by adjusting the raycaster parameters you can affect ram usage vs rendertime, but i dont know how far it can be pushed.