Virtual Memory, How Big?

slim142

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Hi

I would like to know, if I have 2Gbs of RAM, what should my virtual memory be set at? I only know that min and max values should be the same for better perfomance, but I dont know what values should I put in there. Right now is in 2046Mb.
 

Wgfalcon

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2.5 time your max memory (2.5x2gb =5gb) i never allow windows to manage my resources because it attempts to do it on the fly which is always while i'm in the middle of whatever i'm doing(games,av encoding decoding) which causes slowdowns
 

bumster

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The standard virtual memory size to set is actually 1.5 times your amount of RAM, and even Microsoft has suggested this ever since the days of NT 3.5.

Microsoft's suggestion

I would set the minimum and maximum to 3072 for 2GBs of RAM. 5GBs of virtual memory is way too much in my opinion unless you are having "out of virtual memory" errors.
 

tomwaddle

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MS says 1.5 but if you talk to techs or check out PC websites, they'll say 2.5.
I think you'll find people will agree more on setting a fixed amount rather than having the O/S control it. You'll get mixed answers on the actual amount but I'm stickin to 2.5XRam
 

tomwaddle

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Rt click My Computer > Properties
Advanced Tab
Settings button
Advanced Tab
Change button (virtual memory)
Custom size (your call)
 

bumster

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I found a very good explanation that I agree with from http://www.aumha.org/win5/a/xpvm.php


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How big should the page file be?

There is a great deal of myth surrounding this question. Two big fallacies are:

* The file should be a fixed size so that it does not get fragmented, with minimum and maximum set the same
* The file should be 2.5 times the size of RAM (or some other multiple)

Both are wrong in a modern, single-user system. A machine using Fast User switching is a special case, discussed below.)

Windows will expand a file that starts out too small and may shrink it again if it is larger than necessary, so it pays to set the initial size as large enough to handle the normal needs of your system to avoid constant changes of size. This will give all the benefits claimed for a ‘fixed’ page file. But no restriction should be placed on its further growth. As well as providing for contingencies, like unexpectedly opening a very large file, in XP this potential file space can be used as a place to assign those virtual memory pages that programs have asked for, but never brought into use. Until they get used — probably never — the file need not come into being. There is no downside in having potential space available.

For any given workload, the total need for virtual addresses will not depend on the size of RAM alone. It will be met by the sum of RAM and the page file. Therefore in a machine with small RAM, the extra amount represented by page file will need to be larger — not smaller — than that needed in a machine with big RAM. Unfortunately the default settings for system management of the file have not caught up with this: it will assign an initial amount that may be quite excessive for a large machine, while at the same leaving too little for contingencies on a small one.

How big a file will turn out to be needed depends very much on your work-load. Simple word processing and e-mail may need very little — large graphics and movie making may need a great deal. For a general workload, with only small dumps provided for (see note to ‘Should the file be left on Drive C: ? ’ above), it is suggested that a sensible start point for the initial size would be the greater of (a) 100 MB or (b) enough to bring RAM plus file to about 500 MB. EXAMPLE: Set the Initial page file size to 400 MB on a computer with 128 MB RAM; 250 on a 256 MB computer; or 100 MB for larger sizes.

But have a high Maximum size — 700 or 800 MB or even more if there is plenty of disk space. Having this high will do no harm. Then if you find the actual pagefile.sys gets larger (as seen in Explorer), adjust the initial size up accordingly. Such a need for more than a minimal initial page file is the best indicator of benefit from adding RAM: if an initial size set, for a trial, at 50MB never grows, then more RAM will do nothing for the machine's performance.

Bill James MS MVP has a convenient tool, ‘WinXP-2K_Pagefile’, for monitoring the actual usage of the Page file, which can be downloaded here. A compiled Visual Basic version is available from Doug Knox's site which may be more convenient for some users. The value seen for ‘Peak Usage’ over several days makes a good guide for setting the Initial size economically.

Note that these aspects of Windows XP have changed significantly from earlier Windows NT versions, and practices that have been common there may no longer be appropriate. Also, the ‘PF Usage’ (Page File in Use) measurement in Task Manager | Performance for ‘Page File in Use’ include those potential uses by pages that have not been taken up. It makes a good indicator of the adequacy of the ‘Maximum’ size setting, but not for the ‘Initial’ one, let alone for any need for more RAM.
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slim142

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Hey guys, thanks for the info

However, I have some problems. Windows doesnt let me put 5000Mb of page file, it tells me it has to be lower than 4096Mbs so I have left it on 4096Mbs.


Also, I have another question. I read that its better when you have the virtual memory configured on a different drive where windows is so that way, when windows needs virtual memory, it wont put more load on the main drive.

Should I do this and configure my virtual memory from my D drive instead of the C drive?
 

slim142

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Windows is in my Raptor and most of the big programs are in my D drive which is a Seagate 7200.10 barracuda 500gb.

What u guys recommend me to do? leave pagefile in C raptor or D barracuda?
 

randomizer

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Well if your games or whatever are on D drive, I'd say leave the PF on C drive. You dont want windows paging on the same drive it is loading info from. Plus the raptor is faster, so it will be able to read/write to the PF faster.