High page file usage despite tons of free RAM

[Ollie2893]

Hi, I have recently installed an AMDx2 with Win XP Pro x64. From the off the
box was sluggish. I put this down to it only running on 1GB and plugged in
another 2GB of RAM, ie the box now has a total of 3GB of RAM. Performance
remains sluggish, however. I am highly suspicious of the memory management.
Whenever I look at task manager, there always appears to be 2GB of free mem,
ie it will not seem like the m/c using the available memory. Moreover, right
after boot-up with next to nothing running, the m/c begins to use the page
file. I read somewhere that XP by default creates a page file 1.5x the size
of available RAM. Well, my box has a page file of 1.44MB... Just to be
clear, when I look at My Computer/Properties/General, it shows 2.93GB of RAM.
I tried things like /PAE in boot.ini to no avail. Does anyone out there
have any ideas?

 

[Andrew E.]

Open system properties,advanced,virtual memory,change button,set to "let
system manage" click set 2X,close out.As far as performance goes,use xp
utilities (disk clean,defrag,eliminate system restore,temp files etc)....

 

[Ollie2893]

That's System Properties/Advanced/Performance Settings/Advanced/Virtual
Memory/System managed size? Set that - no change in behaviour. Yes, the
allocated page file size has gone up but the problem here was never a lack of
page file size. The issue is that the system starts paging WAY before it
runs out of free RAM. Live example, according to Task Manager:

Physical Memory:
Total: 3078636
Available: 2348936
System Cache: 1893944

PF Usage: 1.17GB

I have NEVER seen Available drop below 2GB - just does not happen. PF
Usage, on the other hand, will quite happily go up.

This is a shared m/c with fast-user switching used extensively. I notice
that switch time between users increases as desktops have more apps open. I
assumed that providing more mem would bring this down. But perhaps inactive
desktops are paged no matter what?

 

[Al Dykes]

That's System Properties/Advanced/Performance Settings/Advanced/Virtual
Memory/System managed size? Set that - no change in behaviour. Yes, the
allocated page file size has gone up but the problem here was never a lack of
page file size. The issue is that the system starts paging WAY before it
runs out of free RAM. Live example, according to Task Manager:

Physical Memory:
Total: 3078636
Available: 2348936
System Cache: 1893944

PF Usage: 1.17GB

I have NEVER seen Available drop below 2GB - just does not happen. PF
Usage, on the other hand, will quite happily go up.

It isn't pagefile size that hurts, it's the rate of physical writes
and reads to it and if the rate is low, paging isn't slowing you down.
This is a matter of "working set" for each application and the system
as a whole.

http://en.wikipedia.org/wiki/Working_set

Going into Task manager/view/select options and picking "Page Fault
Delta" gives you a counter that gives some idea of which apps are
hitting the swap file the most.

perfmon.exe (on every Windows system) is the tool to use to understand
what the system is doing and why. I'm not an expert with it and I'm
suprised there isn't a "Perfmon for Dummies" website. If there is I
can't find it.

I've used perfom to study other aspects of performance but not process
memory usage. Sorry to be a little generic. Pageing has been around
for a long time and my learning of it predates Virtual Memory in Bill
Gates' inplementation of windows.

 

[Ollie2893]

Thanks Al. Did not realize this tool existed. Still, I think it just
reinforces my problem. I would attach a picture, if I knew how to do this
this. Suffice to say that the amount of available memory bottoms out at a
very high level (ca 2GB) and that there is a substantial number of page
faults.

Also, thinking back to virtual memory models, I believe that the sum of
memory required by all active processes is not allowed to exceed the total
available virtual memory space (physical memory + page file). In the example
that I cited, the total amount of memory required by all active processes is
less then the physical memory available. In this situtaion, no memory should
ever be swapped out. I also don't understand what PF allocation the memory
manager would affect at this point: with all processes happily running in
RAM, there is no need to allocate any pages in the PF.