RAM Timings- Command Rate

[Chronic321]

Does anybody know if there is a benefit to setting your RAM to 1t Command Rate VS 2t? I have single 512MB DDR DIMM, it is currently 1t. It seems to run fine but if there is no really benefit (>5%) I would like to turn it down and raise the bus speed or some of the other timings; these are my current timings:
CAS Latency 2
3
3
6
Command Rate 1

Is this pretty good or should I tweak it more?

Thanks