Im pretty sure that CLOD doesn't use more than 4GB of RAM because of the 32bit Exe Chivas. Maybe a more tec headed person will let us know.
Without hacks Clod itself cannot use more than 4Gigs of RAM on 64bit, but your machine can and other applications can, i.e. Clod could use up to 4Gig by itself, Freetrack(in my case) Teamspeak Vent not to mention Windows can use the rest. Unlike in a 32 bit OS where everything is confined to around 3.6Gig IIRC. Thats not to say I don't want a 64bit exe for Clod, au contraire I think it would be fantastic. All I'm saying is that 64 bit OS and some extra headroom can still help with 32 bit apps.
Boko.