What does 32bit Windows see on an AMD64 system with > 4GB ?

[Al Dykes]

I know that each process on a 32bit system are limited to 2/3GB.
That's not the question.

On an AMD64 mobo Does the 32bit OS just ignore the memory
above 4GB ?

Intel has a API for x86 servers called Memory Extensions (I think)
that allows up to at least 16GB, with some magic in the kernel and
Windows Adv Server supports it. Do any of the 64bit Mobos support
this ?

If I run XP/Pro on a dual AMD64 processor with 4GB of each processor
what do I get ?

 

[Star Fleet Admiral Q]

32-bit Home/Pro can only see 4GB period. The hardware is not your
problem, it is the OS's ability to recognize and utilize that
hardware. As you stated, Server OS's have the necessary software
changes to allow memory mapping beyond a 32-bit addressable space, and
of course 64-bit OS's are using 64-bit memory mapping which is far
greater than 4GB, thus eliminating the problem.
As far as which 4GB, that would be the 4GB that can be addressed in a
32-bit address - that you'll need to ask the mobo manufacturer.