Only 3.1GB RAM recognized in P5LD2-VM

[sjledet]

I have four gigs installed but board only recognizes 3.1GB on boot.
Windows reports 3,267,660 KB physical memory.

The manual says "Due to chipset resource allocation, the system may
detext less than 4GB system memory when you instealled four 1Gb DDR2
memory modules."

Soes anybody have any suggestions?

Sterling Ledet Adobe training
http://www.ledet.com/adobe

 

[Roger Hamlett]

I have four gigs installed but board only recognizes 3.1GB on boot.
Windows reports 3,267,660 KB physical memory.

The manual says "Due to chipset resource allocation, the system may
detext less than 4GB system memory when you instealled four 1Gb DDR2
memory modules."

Soes anybody have any suggestions?

Sterling Ledet Adobe training
http://www.ledet.com/adobe

This is normal.
Unfortunately, unless you are running a machine with addressing extensions
enabled, your total memory 'space' addressable by the processor, is 4GB.
The AGP card itself, will map into a huge slice of this, the BIOS, another
large slice, and most I/O cards/devices will also grab big pieces of the
memory area. This is why many boards implement one of the address
extension schemes, which reduces this problem. If your board offers an
address extension mode in the BIOS, try enabling this (you may also have
to modify the XP boot). If not, then there is nothing that can be done,
except to minimise the number of added cards/devices.
The difference can be large. On a machine with two video cards, I have
seen the useable memory change from 3.1GB, to 3.8GB, by enabling these
extensions. Generally though, chipsets aimed at the 'user', rather than
'workstation/server' markets, do not implement such extensions (assuming
that people will probably not try to use 4GB of RAM).

Best Wishes

 

[Paul]

This is normal.
Unfortunately, unless you are running a machine with addressing extensions
enabled, your total memory 'space' addressable by the processor, is 4GB.
The AGP card itself, will map into a huge slice of this, the BIOS, another
large slice, and most I/O cards/devices will also grab big pieces of the
memory area. This is why many boards implement one of the address
extension schemes, which reduces this problem. If your board offers an
address extension mode in the BIOS, try enabling this (you may also have
to modify the XP boot). If not, then there is nothing that can be done,
except to minimise the number of added cards/devices.
The difference can be large. On a machine with two video cards, I have
seen the useable memory change from 3.1GB, to 3.8GB, by enabling these
extensions. Generally though, chipsets aimed at the 'user', rather than
'workstation/server' markets, do not implement such extensions (assuming
that people will probably not try to use 4GB of RAM).

Best Wishes

To add to Roger's info, there is this Intel doc on the Asus site,
and it contains Intel's explanation of the 4GB issues.

http://dlsvr01.asus.com/pub/ASUS/mb/4GB_Rev1.pdf

The 945P chipset doesn't support memory remapping AFAIK. So
chapter 4 of the Intel document won't apply to your board.
If you look for a motherboard like a P5WD2 Premium (955 based),
which lists support for 8GB of memory, it should have a memory
remapping function in the BIOS. One problem with the "memory remapping"
or "memory hoisting" function, is that Asus doesn't always document
the setting in the initial manual, so that makes it difficult to
prove that such a setting exists. (On one of the Asus AMD
motherboards, the code was only added to the BIOS, in the fifth
BIOS release. Such late delivery of features makes it difficult
to be sure what you are getting!) But the combination of memory
remapping, plus an OS that properly supports 4 or more GB
of remapped memory, would be a step in the right direction.

I suspect very few users get this working right, as I've never
seen a "success" posting from any user who has asked this
question. Maybe some day we'll get a little useful feedback.

HTH,
Paul

 

[Robert Hancock]

I have four gigs installed but board only recognizes 3.1GB on boot.
Windows reports 3,267,660 KB physical memory.

The manual says "Due to chipset resource allocation, the system may
detext less than 4GB system memory when you instealled four 1Gb DDR2
memory modules."

On that motherboard there is no way around this. The MMIO regions for
devices, video cards, etc. cover up the 800MB of unusable memory.

Most Athlon 64 boards have the ability to remap memory in such regions
above 4GB (this capability is part of the on-chip memory controller) but
normal Intel desktop chipsets do not. To make use of this, you also need
either Linux, 64-bit Windows or a server version of Windows, as normal
WinXP will not use memory above 4GB.

 

[John Lewis]

I have four gigs installed but board only recognizes 3.1GB on boot.
Windows reports 3,267,660 KB physical memory.

The manual says "Due to chipset resource allocation, the system may
detext less than 4GB system memory when you instealled four 1Gb DDR2
memory modules."

Soes anybody have any suggestions?

yes, install Windows XP 64, which recognizes up to 12Gbyte of RAM.
However, you will also need all the required 64-bit drivers for your
motherboard and peripherals, and various 32-bit applications do not
yet have 64-bit-compatible patches.

This particular Windows XP (32) limitation is well-known.

John Lewis

 

[DaveW]

That motherboard can ONLY recognize up to 3.1 GB of useable RAM, even if you
install 4 GB. It's a design decision they made.

 

[news.news]

This is ASUS designed problem.

 

[Paul]

This is ASUS designed problem.

Even Intel has the problem with their own motherboard.

http://www.intel.com/support/motherboards/server/sb/cs-016594.htm

The problem is caused by trying to do both memory mapped
I/O and 4GB of memory, on a 32 bit architecture. There isn't
room to do both, so some memory must be discarded. It is
an architecture limitation, and has nothing to do with who
designs the motherboard.

Paul

 

[news.news]

I remeber Intel make it very clear in the specification.
However on P5LD2. The specification say it support up to 4G.

 

[Robert Hancock]

Even Intel has the problem with their own motherboard.

http://www.intel.com/support/motherboards/server/sb/cs-016594.htm

The problem is caused by trying to do both memory mapped
I/O and 4GB of memory, on a 32 bit architecture. There isn't
room to do both, so some memory must be discarded. It is
an architecture limitation, and has nothing to do with who
designs the motherboard.

Well, it's mainly a chipset limitation - Intel could have put memory
remapping support into the chipset, however they chose not to, thus the
inability to remap the covered-up memory above 4GB.