> My "64 bit" CPU has 36 bit physical addresses and 48 bit virtual addresses.
Just to clarify for anyone that doesn't catch what you mean and thinks PAE is the devil:
x86-64 CPUs must support in PAE when operating in long mode (64 bit mode). Further the version of PAE used is 'classic PAE' with an additional translation layer added to get some more physical address space. In other words even 64bit CPUs don't have a real 64bit physical address space, they still use PAE to access large amounts of ram.
Just to clarify for anyone that doesn't catch what you mean and thinks PAE is the devil:
x86-64 CPUs must support in PAE when operating in long mode (64 bit mode). Further the version of PAE used is 'classic PAE' with an additional translation layer added to get some more physical address space. In other words even 64bit CPUs don't have a real 64bit physical address space, they still use PAE to access large amounts of ram.