The March issue of Maximum PC had a seven page article about memory. Much of the information was new to me.
Of special interest were instructions on tweaking memory. They stated that, in general, memory manufacturers are very conservative in their memory timings. In a series of experiments, they determined that the following adjustments gained them 3% faster memory performance when tested with SiSoft Sandra..
Lower CAS Latency from 2.5 to 2
Lower RAS to CAS (tRCC) Delay from 3 to 2
Lower RAS Precharge (tRCP) from 3 to 2
Lower Active to Precharge (tRAS) from 6 to 5
Lower command rate from 2T to 1T
They cautioned that improvements vary and that motherboards play a roll in the success of this tweak.