> So what is the ceiling on 32-bit processors for RAM? Most of the 64-bit
> vendors are pushing Athalon64 and G5 as "breaking the 4GB barrier", and even
> I can do the math on 2^32. All these 64-bit vendors, then, are talking
> about the limit on ram *per application* and not per machine?
64-bit CPU on 64-bit OS. Up to physical address limit for anything and
everything.
64-bit CPU on 32-bit OS. Up to 4GB minus the kernel allocation -- which
is usually 2GB on Windows and Linux. On Windows, you can up this to 3GB
by using the /3GB switch. Linux requires a kernel recompile. PAE is then
used to "move" the memory window to point to different areas of the
physical memory.