process memory limitations

[Maimon Oded]

Hi,

I've a question about per process memory allocation limitation.

if i've a 32bit machine, with RHEL 4, what are the limitation of memory 
that each process can allocate?

if i've a 64bit machine, with RHEL 4, and i'm using a 32bit program, 
what are the limitation of memory that each process can allocate?

Thanks,

Oded.