P5WD2 and 4x1GB

[Barry Comer]

Folks:

I have an Asus P5WD2 motherboard with four 1GB DIMMs and Windows XP SP2 only
sees 3GB of
my memory. The BIOS reports 4GB with 0GB allocated. What can I do to see the
missing 1GB of memory?

Thanks
Barry

 

[Barry Comer]

I tried XP-64bit and it sees all of the memory.

I know 32-bit is limited to 4GB but my Dell at work has the same amount of
RAM and it
reports 3.7GB under XP SP2.

 

[Stephan Grossklass]

Folks:

I have an Asus P5WD2 motherboard with four 1GB DIMMs and Windows XP SP2 only
sees 3GB of
my memory. The BIOS reports 4GB with 0GB allocated. What can I do to see the
missing 1GB of memory?

You must remap the PCI address ranges to somewhere further up - there
should be a BIOS option for this.

Stephan

 

[Robert Hancock]

I tried XP-64bit and it sees all of the memory.

I know 32-bit is limited to 4GB but my Dell at work has the same amount of
RAM and it
reports 3.7GB under XP SP2.

That machine probably is using less address space for memory-mapped I/O.
See if the BIOS has an option to remap some memory above 4GB. However, I
don't know if regular XP Pro will recognize such memory, I think it may
be just the server OSes that do.

If you really want all 4GB then XP 64-bit is probably the best option.

 

[Tim]

Also do a thorough reading of the /3GB and /PAE switches on the MS site.
If you have 4GB then by default the memory is split 2gb for app address
space and 2gb for system. With the 3GB switch, this enables 1 GB for system
and 3GB for apps - if you have apps that really need over 2GB then this will
be very beneficial.

/PAE is largely irrelevant - I have included it as some people may confuse
you with it. I suggest you get the real story from the MS web site and
conclude for your self that it is irrelevant (or not) in your specific case.

Notes:

There is a RAM reporting bug in XP SP2 where under certain circumstances
only 3GB is reported.

There is a known error with one or more of the Office apps with exactly 4GB
physical RAM.

- Tim