Windows XP Virtual Memory

[Chris McMahon]

I have a Windows XP system with 1.5GB of RAM, but Windows seems to
insist on using Virtual Memory even when there is plenty of physical
memory left (>800MB).

If I open multiple programs and switch between them, Windows will
usually favor storing the inactive program in Virtual Memory even
though most of my physical memory is still free. So when I switch
back to the inactive program, I have to wait for it to be loaded from
disk.

Is there any way to force Windows XP to use Phyical Memory in favor of
Virtual Memory?

 

[Gerry]

Try this, go to control panel, double click system,
click on advanced tab, on the Performance pane, click
settings, select the advanced tab and then at the bottom,
virtual memory, click change, pick your hard drive in the
top pane, select the option for no paging file click set
and then ok. Reboot system. You will probably get a
message about not having a paging file. Just ignore it.
Beware though, if you ever open up enough problems that
will use all your RAM, your system will probably crash so
be careful. Good luck.

 

[Ron Martell]

I have a Windows XP system with 1.5GB of RAM, but Windows seems to
insist on using Virtual Memory even when there is plenty of physical
memory left (>800MB).

If I open multiple programs and switch between them, Windows will
usually favor storing the inactive program in Virtual Memory even
though most of my physical memory is still free. So when I switch
back to the inactive program, I have to wait for it to be loaded from
disk.

Is there any way to force Windows XP to use Phyical Memory in favor of
Virtual Memory?

Windows will *always* use the virtual memory paging file space to
satisfy the memory address requirements for the unused portions of
memory allocation requests.

By definition Windows must identify specific memory address space to
satisfy all of the memory allocation requests that are issued by
windows components, device drivers, and application programs. And for
a variety of reasons these memory allocation requests are typically
overstated in comparison to the amount of memory that is actually used
under normal circumstances.

So what the memory manager does is to assign RAM only to those
portions of the requested memory that is actually being used and to
map the unused portions to locations in the page file. Note that no
disk activity is required for this - only a notation in the memory map
tables maintained by the CPU. And if some of the previously unused
memory is later required to be used then that memory portion can be
instantaneously remapped to an available location in RAM, again simply
by changing the table.

The only "dangerous" aspect of the type of situation that you describe
would be if Windows were actually moving memory content from RAM to
the page file while there still was a significant quantity of unused
RAM available. Unfortunately Windows does not provide an easy way of
determining how much, if any, memory content has been relocated from
RAM to the page file. However a free utility that will report this
figure can be downloaded from
http://www.dougknox.com/xp/utils/xp_pagefilemon.htm or from
http://billsway.com/notes_public/WinXP_Tweaks

If you download this utility you should find that the actual page file
usage will be zero or at least very little.

Hope this explains the situation.

Good luck


Ron Martell Duncan B.C. Canada
--
Microsoft MVP
On-Line Help Computer Service
http://onlinehelp.bc.ca

"The reason computer chips are so small is computers don't eat much."

 

[Chris McMahon]

Thanks for the utility. I tried it out and it's showing my PageFile
size to be between 190MB and 250MB, even though I have about 700MB
available physical memory (according to the Performance tab of Task
Manager).

 

[Chris McMahon]

I'm tempted to disable Virtual Memory completely, but I've read that
that can be dangerous and some programs will blow up if you try that.

 

[Alex Nichol]

I have a Windows XP system with 1.5GB of RAM, but Windows seems to
insist on using Virtual Memory even when there is plenty of physical
memory left (>800MB).

If I open multiple programs and switch between them, Windows will
usually favor storing the inactive program in Virtual Memory even
though most of my physical memory is still free. So when I switch
back to the inactive program, I have to wait for it to be loaded from
disk.

Unless you have some third party program that is using the page file
directly for its own ends, I think you are misinterpreting how the VM
system is working. What it may put notionally in page file is pages
allocated to programs which have never been brought into use, and
therefore there is mo point in having them in RAM - this may easily
a,mount to hundreds of MB. The Task Manager report on page file in use
is highly misleading. See my page www.aumha.org/win5/a/xpvm.htm for
more

 

[Ron Martell]

Thanks for the utility. I tried it out and it's showing my PageFile
size to be between 190MB and 250MB, even though I have about 700MB
available physical memory (according to the Performance tab of Task
Manager).

The size of the page file is not the critical value.

What does the utility say for Current Pagefile Usage and for Session
Peak Usage?


Ron Martell Duncan B.C. Canada
--
Microsoft MVP
On-Line Help Computer Service
http://onlinehelp.bc.ca

"The reason computer chips are so small is computers don't eat much."

 

[Chris McMahon]

Sorry, I meant Pagefile Usage, not Pagefile Size.

Here are some numbers:

Current Pagefile Usage: 259 MB
Session Peak Usage: 538 MB
Current Pagefile Size: 1024 MB

 

[Chris McMahon]

Thanks for the link. I followed the advice on that link and set my
minimum Page file size to 100MB (I left max at 1.5GB). And after
using only about 400MB of my physical memory (out of 1.5GB physical),
Windows popped up a box saying it needed to increase the size of
Virtual memory.

Why does Windows XP do this? Is it's memory system brain-dead or does
it have a legitimate reason for having such a strong affinity for hard
disk based memory over RAM? Or do I have something configured wrong
on my system?

 

[Ron Martell]

Sorry, I meant Pagefile Usage, not Pagefile Size.

Here are some numbers:

Current Pagefile Usage: 259 MB
Session Peak Usage: 538 MB
Current Pagefile Size: 1024 MB

And what does Task Manager - Performance report for "Available
Physical Memory" when this is going on?

Something seems to be amiss here.


Ron Martell Duncan B.C. Canada
--
Microsoft MVP
On-Line Help Computer Service
http://onlinehelp.bc.ca

"The reason computer chips are so small is computers don't eat much."

 

[Alex Nichol]

Thanks for the link. I followed the advice on that link and set my
minimum Page file size to 100MB (I left max at 1.5GB). And after
using only about 400MB of my physical memory (out of 1.5GB physical),
Windows popped up a box saying it needed to increase the size of
Virtual memory.

Why does Windows XP do this? Is it's memory system brain-dead or does
it have a legitimate reason for having such a strong affinity for hard
disk based memory over RAM? Or do I have something configured wrong
on my system?

This smells like some third party software getting in on the act.
Either one of the 'Free up' or 'Manage' RAM programs, which often have
exactly this effect - pushing things into page file (quite
unnecessarily) in order to produce a spurious 'lots of free/available
memory'. If you have one throw it out as far as you can. One such is
the 'tune up' aspect of TweakXP, Or possibly something like
PhotoShop, which (in the past at least) has grabbed an area of page file
for itself to manage.

 

[Rick Chauvin]

Alex Nichol wrote:

[....]

See my page www.aumha.org/win5/a/xpvm.htm for more

That's a Great article, thanks Alex

 

[Guest]

----- Chris McMahon wrote: ----

I have a Windows XP system with 1.5GB of RAM, but Windows seems t
insist on using Virtual Memory even when there is plenty of physica
memory left (>800MB)

If I open multiple programs and switch between them, Windows wil
usually favor storing the inactive program in Virtual Memory eve
though most of my physical memory is still free. So when I switc
back to the inactive program, I have to wait for it to be loaded fro
disk

Is there any way to force Windows XP to use Phyical Memory in favor o
Virtual Memory