I haven't done any tweaking, just a simple comparison between -d32 and -d64. My current working theory is that the JITed code takes advantage of the general im

I haven't done any tweaking, just a simple comparison between -d32 and -d64. My current working theory is that the JITed code takes advantage of the general improvement of 64 bit mode (eg greater number of registers). But right now performance isn't an issue, I'm running in 64 bit mode for the memory not the speed.