does dimension 4600 support solaris 10 64 bit.

moved an hard drive from del 3100 to dell 4600. but unfotunately the OS system which was formaly working properly in dell 3100 as solaris10 x86 64 bits, refuse to work properly in dell 4600. the OS keeps coming out as 32 bit and still will not work properly. I was wondering if dell 4600 dos not support 64 bit of sun solaris OS. pls can anyone throw light into this. i will be greatful.