XP only sees 3MB of my 4MB of RAM

[Guest]

I have a notebook PC running XP Media Center Edition on which I installed 4
GB of memory (2 x 2 GB modules). Various utilities show that both modules
are properly installed totaling 4 GB of memory.

However, "My Computer\System Properties" shows only 2.99GB of RAM available.

How can I make XP see and use more of my 4 GB of memory?

Can I configure my PC to free up more memory?

Thank you.

Jeff

 

[John John (MVP)]

There is really nothing much that you can do to overcome this memory
addressing limitation on 32-bit Windows workstation/client operating
systems. The only way around the problem is to move to a 64-bit client
operating system.

John

 

[HeyBub]

I have a notebook PC running XP Media Center Edition on which I
installed 4 GB of memory (2 x 2 GB modules). Various utilities show
that both modules are properly installed totaling 4 GB of memory.

However, "My Computer\System Properties" shows only 2.99GB of RAM
available.
How can I make XP see and use more of my 4 GB of memory?

You can't. You've hit the wall.

Can I configure my PC to free up more memory?

You can't. You've hit the wall.

 

[jim]

How much RAM is on your video card? The 4GB limit includes your video
RAM so if the total is over 4 you must see less. Other devices have
memory also which will also subtract from the 4GB limit such as audio
and network devices but they usually impact your total memory to a much
smaller amount. So the reality is you most likely have 4GB of memory
but it is made up form your other devices plus the RAM you installed.

 

[Tim Slattery]

I have a notebook PC running XP Media Center Edition on which I installed 4
GB of memory (2 x 2 GB modules). Various utilities show that both modules
are properly installed totaling 4 GB of memory.

However, "My Computer\System Properties" shows only 2.99GB of RAM available.

See http://members.cox.net/slatteryt/RAM.html for an explanation.

 

[Bob I]

Configure the video to use up less ram, and disable in BIOS any hardware
that you don't use. It is the memory addresses being used up by other
hardware that precludes windows from using them to provide access to the
RAM.

 

[Guest]

Thank you all for the explanations.

Memory is cheap today, so it does not really matter.

But the interesting question comes up: is more ram available for "program
use" if the same PC had 3 GB installed vs 4 GB, or it makes no difference?

Jeff

 

[Bob I]

It depends

Memory type Limit in 32-bit Windows Limit
User-mode virtual address space for each 32-bit process 2 GB

Up to 3 GB with IMAGE_FILE_LARGE_ADDRESS_AWARE and 4GT

Taken from
http://msdn.microsoft.com/en-us/library/aa366778.aspx#memory_limits

 

[Guest]

What would be the recommended virtual memory size I should set now?

Jeff

 

[Bob I]

1GB would probably be plenty.

What would be the recommended virtual memory size I should set now?

Jeff

 

[Guest]

Thank you.

1GB would probably be plenty.

 

[John John (MVP)]

It would make no difference, the RAM is without address and it cannot be
used by the operating system or any other applications.

John

 

[Guest]

Thank you John andeveryone else. You have been most informative.

Jeff

 

[Ken Blake, MVP]

I have a notebook PC running XP Media Center Edition on which I installed 4
GB of memory (2 x 2 GB modules).

Why? That's more memory than most people can make effective use of.
How much RAM you need for good performance is *not* a
one-size-fits-all situation. You get good performance if the amount of
RAM you have keeps you from using the page file, and that depends on
what apps you run. Most people running a typical range of business
applications find that somewhere around 512MB works well, others need
more. Almost anyone will see poor performance with less than 256MB.
Some people, particularly those doing things like editing large
photographic images, can see a performance boost by adding even more
than 512MB--sometimes much more.

If you are currently using the page file significantly, more memory
will decrease or eliminate that usage, and improve your performance.
If you are not using the page file significantly, more memory will do
nothing for you.

Various utilities show that both modules
are properly installed totaling 4 GB of memory.

However, "My Computer\System Properties" shows only 2.99GB of RAM available.

All 32-bit client versions of Windows (not just Vista/XP) have a 4GB
address space. That's the theoretical upper limit beyond which you can
not go.

But you can't use the entire 4GB of address space. Even though you
have a 4GB address space, you can only use *around* 3.1GB of RAM.
That's because some of that space is used by hardware and is not
available to the operating system and applications. The amount you can
use varies, depending on what hardware you have installed, but can
range from as little as 2GB to as much as 3.5GB. It's usually around
3.1GB.

Note that the hardware is using the address *space*, not the actual
RAM itself. The rest of the RAM goes unused because there is no
address space to map it too.

How can I make XP see and use more of my 4 GB of memory?

You can not.

Can I configure my PC to free up more memory?

No.

 

[Guest]

Thank you. Fortunately it was not a major expenditure....

Jeff

 

[Ken Blake, MVP]

Thank you. Fortunately it was not a major expenditure....

You're welcome. Glad to help. And glad it wasn't a major expenditure.