CPU benchmark advice
For timing I'm just running the *nix command "time ./robocode.sh -nodisplay -battle battles/diamond.battle". For Robocode startup time (including JVM startup but not just that), I'm just roughly estimating by watching the command line output.
Here's some fun... I tried using my motherboard's "automatic overclocking" functionality where it tries t, and it decided it could get it up from 3.2GHz to 4.2GHz (+30%). Both Windows and Linux booted fine, so initially I thought it was stable, and it ran one robocode battle at a time fine, but as soon as I tried to run multiple in parallel, the JVM kept crashing and it became apparent that the +30% overclock was not stable despite OSs booting fine. Interesting thing was, the +30% overclocking seemed fine thermally even with the stock cooler, it just had other stability issues.
I'm now running a more modest +12.5% CPU overclock, and I got the Diamond versus Diamond runs down to 12.837 seconds-per-battle, running 6 in parallel. This is still with memory running at 1600MHz, so I guess what I was hitting before wasn't purely a memory bottleneck anyway. Also, huh, 22.5% increase from a 12.5% CPU overclock...