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Is my paging file really turned off?

Posted: Tue Mar 20, 2007 2:12 pm
by BlueDevilTide
I have a gigabyte of RAM on my T23 and am using XP Pro SP2. I wanted to turn off my paging file to increase performance. Through the My Computer-->Properties path, I turned off the virtual memory by changing the Paging File Size For All Drives to be 0MB.

However, in task manager, I have it set to view VM Size in addition to Mem Usage. Every application also has a VM usage as well. Overall memory, in the status bar of Task Manager has 926M listed, which sounds about right with a 1024MB system (though where did the rest go?)

Using TuneUp Utilities Process Manager (a sort of Task Manager on steroids), it lists a Paging File of 949,072KB, of which 533,032KB is used. Another info box lists Memory as 1,047,472KB as the total level, of which 379,968KB is available.

All of this make me wonder if the paging file is really completely turned off. How can I ensure this besides the My Computer-->Properties method?

Sorry for the long post. Just wanted to be thorough. Thanks.

Posted: Tue Mar 20, 2007 2:33 pm
by Purcy
There is a tweak for Windows XP that will make your computer use your real RAM first before going to the page file memory; perhaps institute that tweak instead of trying to stop the pageing system. I don't know why I thought I read somewhere that Windows won't allow a 0MB page file, maybe I was hallucinating.

Posted: Tue Mar 20, 2007 2:40 pm
by ronbo613
Windows XP contains several tweakable memory settings in the registry, one of which is the DisablePagingExecutive registry key. This controls whether the operating system will transfer its essential driver and kernel files to the 'virtual memory' (the page file on the hard disk). It defaults to allowing this.

Obviously, transferring portions of the system to hard drive memory can considerably slow things down, and it appears that Windows XP does this periodically, whether or not the system is actually low on physical memory (RAM). If you have 256MB of system memory or more, try this registry tweak to force Windows to keep its operating data in main memory:

Open Regedit.

Navigate to HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Session Manager\Memory Management.

Select the DisablePagingExecutive value to '1'

Posted: Tue Mar 20, 2007 2:43 pm
by Purcy
Ronbo, thanks for posting this; I was trying to find that tweak again, so I could use it. I did read that Windows XP does switch to the page file even if it is not low on resources in main RAM, I wonder who thought of that?? :roll:

Posted: Tue Mar 20, 2007 3:04 pm
by RealBlackStuff
Certain programs (such as Photoshop) REQUIRE a paging file, otherwise they won't function.
The most stable result would be to create a fixed-size paging file of max. 1.5GB. If you have 2 hard disks, you can create a small 100mb paging file in the Windows partition and the rest of the paging file at the front of the fastest other hard disk.
On my main PC with 2GB memory the paging file is fixed 768MB.

This works for me, but people have written 'books' about this....

Posted: Tue Mar 20, 2007 3:39 pm
by jdhurst
Page files are statically located on the disk, and in my experience, cause no performance drag whatever. So perhaps it is best just to let Windows assign it. ... JD Hurst

Posted: Tue Mar 20, 2007 3:47 pm
by Purcy
realblackstuff wrote: On my main PC with 2GB memory the paging file is fixed 768MB.
I have mine set at a static 768MB, with 512 RAM, I notice no difference from when it was set to flucuate. I do use PhotoShop so need the extra memory.

Posted: Tue Mar 20, 2007 3:57 pm
by ronbo613
On my workstation, with 2G of RAM, I played around with the pagefile, setting it myself, moving it to another hard drive, etc., and to be honest, I didn't notice any real difference, even when using Photoshop, Premiere, Illustrator and Sony Vegas.
I would probably let Windows manage the pagefile(unless you are really, really short of hard drive space), try that registry tweak and see what happens.

Posted: Sat Mar 24, 2007 1:07 pm
by ashleys
I suggest if you REALLY want to know what you're doing when dealing with Windows Virtual Memory buy something like Windows Internals 4th Edition by Russinovich and Solomon.
Chapter 7 is on memory management. It gives both a good basic outline of how the concept of Virtual Memory works and certain Windows specific details.

On a system with enough RAM, the Disable Paging Executive will make no difference. Those routines will say loaded and not be subject to a page steal.