[Deux]

Surprised no one has mentioned this. On Nehalem, 2GB sticks are 4-6 seconds faster than 1GB sticks everything else equal.

maxmem=600 is a good value to start with.

The gains from CW aren't huge, usually a few seconds. I'd start with 1896MB and CDT enabled. This provides some gains on most systems but can still be heavily tweaked for further improvement.