I'm experimenting with the -parallel flag and finding that using 2 parallel threads is slower than a single thread, and using 3 is slower still. I have 4 cores on my machine, FYI. $ time java -jar HeatBugs.jar -for 10000 -repeat 4 -parallel 1 -quiet real 0m4.514s user 0m6.098s sys 0m0.749s $ time java -jar HeatBugs.jar -for 10000 -repeat 4 -parallel 2 -quiet real 0m4.799s user 0m12.019s sys 0m1.437s $ time java -jar HeatBugs.jar -for 10000 -repeat 4 -parallel 3 -quiet real 0m5.972s user 0m21.190s sys 0m2.933s What's the deal here? Joey