Windows XP Pro and Memory Above 2GB

[HAWK72758]

I am running Windows XP Pro SP3 and recently added 4GB of memory for a total
of 5GB. I understand that Windows XP Pro (32bit) has a limitation and can see
no more than 4GB. When I pull up the system properties it is only reporting
3GB. The bios is seeing all of it so I am baffeled.

My question is this, is Windows really only seeing 3GB or is it seeing 4GB
with 1GB in some kind of reserve state? If it's really only seeing 3GB how do
I make it recognize up to it's limits?

Thanks

 

[Bob Willard]

I am running Windows XP Pro SP3 and recently added 4GB of memory for a total
of 5GB. I understand that Windows XP Pro (32bit) has a limitation and can see
no more than 4GB. When I pull up the system properties it is only reporting
3GB. The bios is seeing all of it so I am baffeled.

My question is this, is Windows really only seeing 3GB or is it seeing 4GB
with 1GB in some kind of reserve state? If it's really only seeing 3GB how do
I make it recognize up to it's limits?

Thanks

The 32-bit versions of XP have a 4GB address space. Some of that
address space is used to map to I/O devices, and the rest is available
to address RAM. 3GB or so, depending on the MoBo and the I/O stuff
plugged in, is the max. addressable RAM. That's life.

 

[JS]

It's not uncommon for the BIOS to only report
3 or 3.2GB of memory.

Of the 5GB you have installed you 32Bit OS
will only be able to use about 3.2GB.

So unless you plan to dual boot to a 64Bit
version of Windows you might as well remove
1GB as all it going to do is use power and if it's
not an identical match to the other 4GB could
even slow down your ram performance a tad.

 

[Shenan Stanley]

I am running Windows XP Pro SP3 and recently added 4GB of memory
for a total of 5GB. I understand that Windows XP Pro (32bit) has a
limitation and can see no more than 4GB. When I pull up the system
properties it is only reporting 3GB. The bios is seeing all of it
so I am baffeled.

My question is this, is Windows really only seeing 3GB or is it
seeing 4GB with 1GB in some kind of reserve state? If it's really
only seeing 3GB how do I make it recognize up to it's limits?

I guess you didn't take the time to actually understand what you said you
understand about the limitations of Windows XP (32-bit) and memory. ;-)

You might read up some more....
http://www.google.com/search?hl=en&q="Windows+XP"+32-bit+memory+4GB+explanation

Perhaps this link:
http://members.cox.net/slatteryt/RAM.html

Or a simplified (mostly correct) with pictures version:
http://rogerngo.blogspot.com/2009/01/explanation-of-4gb-limit-on-32-bit.html

Essentially - you will likely see between 2.75GB and 3.5GB of memory in
Windows XP 32-bit depending on your hardware - as it is being used elsewhere
by your system.

 

[HAWK72758]

I guess you didn't take the time to actually understand what you said you

understand about the limitations of Windows XP (32-bit) and memory. ;-)

As a matter of fact I DID understand EXACTLY what I was saying. I know that
the 32 bit version has a 4gb limit and the 5gb I had planned on removing. I
have an Asus MB that can handle up to 8gb but since I'm not running software
to handle that amount it made no sense to put that much in.

What I was trying to understand was why the system properties reported 3gb
when Windows XP Pro can handle 4gb. Because it only reported 3gb I assumed
that perhaps the othe 1gb was in reserve for other system uses and theryby
not showing the full 4gb.

I simply wanted to know if that was the case.

 

[HAWK72758]

Hi JS,

The bios is reporting all 5gb. It's windows that is seeing only 3gb out of
the 4gb it can supposedly handle up to. I have removed the 5th chip so that
only 4gb remain.

 

[HAWK72758]

Thanks Bob.....You answered my question. I had a feeling that while windows
reported 3 of the 4gb of memory that the 4th was probably reserved for
devices and such.

 

[Paul]

As a matter of fact I DID understand EXACTLY what I was saying. I know that
the 32 bit version has a 4gb limit and the 5gb I had planned on removing. I
have an Asus MB that can handle up to 8gb but since I'm not running software
to handle that amount it made no sense to put that much in.

What I was trying to understand was why the system properties reported 3gb
when Windows XP Pro can handle 4gb. Because it only reported 3gb I assumed
that perhaps the othe 1gb was in reserve for other system uses and theryby
not showing the full 4gb.

I simply wanted to know if that was the case.

If you want another experiment to try, see if your BIOS has an option
for remapping/memory hoisting. Try both with it enabled and disabled,
and see if the available memory is slightly greater. It might make
the difference of 3GB or 3.2GB or the like.

Paul

 

[JS]

That good news, if your BIOS can see the 5th Gig,
you can take full advantage of a 64bit OS. If you
downloaded the 64Bit version of Windows 7, give it
a spin on a spare drive, disconnect your current XP
drive before doing so.

 

[Shenan Stanley]

I am running Windows XP Pro SP3 and recently added 4GB of memory
for a total of 5GB. I understand that Windows XP Pro (32bit) has a
limitation and can see no more than 4GB. When I pull up the system
properties it is only reporting 3GB. The bios is seeing all of it
so I am baffeled.

My question is this, is Windows really only seeing 3GB or is it
seeing 4GB with 1GB in some kind of reserve state? If it's really
only seeing 3GB how do I make it recognize up to it's limits?

I guess you didn't take the time to actually understand what you
said you understand about the limitations of Windows XP (32-bit)
and memory. ;-)

You might read up some more....
http://www.google.com/search?hl=en&q="Windows+XP"+32-bit+memory+4GB+explanation

Perhaps this link:
http://members.cox.net/slatteryt/RAM.html

Or a simplified (mostly correct) with pictures version:
http://rogerngo.blogspot.com/2009/01/explanation-of-4gb-limit-on-32-bit.html

Essentially - you will likely see between 2.75GB and 3.5GB of
memory in Windows XP 32-bit depending on your hardware - as it is
being used elsewhere by your system.

As a matter of fact I DID understand EXACTLY what I was saying. I
know that the 32 bit version has a 4gb limit and the 5gb I had
planned on removing. I have an Asus MB that can handle up to 8gb
but since I'm not running software to handle that amount it made no
sense to put that much in.

What I was trying to understand was why the system properties
reported 3gb when Windows XP Pro can handle 4gb. Because it only
reported 3gb I assumed that perhaps the othe 1gb was in reserve for
other system uses and theryby not showing the full 4gb.

I simply wanted to know if that was the case.

Right.

If you understood what you thought you understood (not what you wrote - what
you said you understood) then you would have visited the links I gave you
and actually understood how the 4GB was seen by the 32BUT OS. Nothing
complicated and I explained it clearly as well.

You said, "I understand that Windows XP Pro (32bit) has a limitation and can
see no more than 4GB.", but that statement alone shows you did not
understand all the details of what you thought you were saying. ;-)

 

[Ian D]

If you want another experiment to try, see if your BIOS has an option
for remapping/memory hoisting. Try both with it enabled and disabled,
and see if the available memory is slightly greater. It might make
the difference of 3GB or 3.2GB or the like.

Paul

The BIOS memory remap should not be used with a 32 bit OS.
With 32 bit XP, enabling the remap can result in the OS having
only 2GB accessible. The remap will map the 4th GB into the
3rd GB. With a 64 bit OS it would map the 4th GB into the
GB beyond the highest installed memory. For a 4GB system,
that would be the 5th GB.

 

[Paul]

The BIOS memory remap should not be used with a 32 bit OS.
With 32 bit XP, enabling the remap can result in the OS having
only 2GB accessible. The remap will map the 4th GB into the
3rd GB. With a 64 bit OS it would map the 4th GB into the
GB beyond the highest installed memory. For a 4GB system,
that would be the 5th GB.

That is why it's an experiment

Paul