java runtime speed comparison

My friend's new Mac arrived today and I wanted to compare the JVM speed to my PC.

The code counts the primes between 2 and 10000000, it took:

158 seconds on cogshiftingman's old PC (800MHz, 256MB ram, WinXP)
93 seconds on my PC Server (Compaq 2x733MHz, 1GB ram, Win2000 Server)
86 seconds on upstartn's PC (Duron 1GHz, 512MB ram, Win 2000)
70 seconds on my Mac (G4, 1GHz, 1GB ram, OSX 10.2)
62 seconds on cogshiftingman's PC (Xeon 2x1.7Ghz, 1GB ram, Win2003)
54 seconds on my PC (P4, 2GHz, 1GB ram, Win200)
47 seconds on davidschloss's Mac (G5, 2x2GHz, 2GB ram, OSX 10.2)
45 seconds on chazcross's PC (Amd 2.2GHz, 512MB ram, WinXP)
40 seconds on mostdangerous's PC (P3 2.8GHz, 512 RAM, WinXP)
34 seconds on khalidz0r's Hyperthreading PC (P4, 3.066GHz, 1GB RAM, Win XP)
32 seconds on kion's Hyperthreading PC (P4, 3.2GHz, 2GB RAM, Win XP)