Consensus re swap file size?

[Terry Pinnell]

A few years ago there used to be much (sometimes heated) discussion
about the 'optimum' size of the XP swap file. I vaguely recall that
the widely-quoted rule of thumb of using 1.5 times the size of your
RAM was disowned by several experts.

So I was surprised to find that, having recently changed my own setup
to 'System Managed', that this rule is apparently being used by the OS
itself. (In my case, with 512 MB, it has reserved 767 MB.)

Is this rule indeed 'respectable' again please?

 

[Z]

A few years ago there used to be much (sometimes heated) discussion
about the 'optimum' size of the XP swap file. I vaguely recall that
the widely-quoted rule of thumb of using 1.5 times the size of your
RAM was disowned by several experts.

So I was surprised to find that, having recently changed my own setup
to 'System Managed', that this rule is apparently being used by the OS
itself. (In my case, with 512 MB, it has reserved 767 MB.)

Is this rule indeed 'respectable' again please?

Article ID : 314482
Last Review : May 13, 2004
Revision : 1.0
....
The default, or recommended, paging file size is equal to 1.5 times the
total RAM. ...

 

[Plato]

A few years ago there used to be much (sometimes heated) discussion
about the 'optimum' size of the XP swap file. I vaguely recall that
the widely-quoted rule of thumb of using 1.5 times the size of your
RAM was disowned by several experts.

So I was surprised to find that, having recently changed my own setup
to 'System Managed', that this rule is apparently being used by the OS
itself. (In my case, with 512 MB, it has reserved 767 MB.)

Is this rule indeed 'respectable' again please?

Best bet is to just let windows do its thing with the page/swap. Keep in
mind that while it may reserve that much, it doesnt mean its using that
much.

 

[Uncle John]

Terry

My PC has 4 GB Ram: if virtual memory is set to system managed it will be
set to 3.5 GB. The system page file size in Windows XP+SP2 may ignore the
user settings for Virtual Memory in Control panel: they may revert to a
system default if the Registry has more than one setting for
HKLM\System\ControlSetnnn
where "nnn" is the number of the last ControlSet before CurrentControlSet.

Though Windows does not necessarily use all the pagefile set, it will
reserve disk space which is then not available to the user for applications
and processes.

You can check how large your system managed page file is on the DISK by
looking for pagefile.sys in the root directory of C:\ and checking the
properties. Sometimes they are quite different to the settings in Control
Panel for Virtual Memory
Uncle John

 

[Terry Pinnell]

Terry

My PC has 4 GB Ram: if virtual memory is set to system managed it will be
set to 3.5 GB. The system page file size in Windows XP+SP2 may ignore the
user settings for Virtual Memory in Control panel: they may revert to a
system default if the Registry has more than one setting for
HKLM\System\ControlSetnnn
where "nnn" is the number of the last ControlSet before CurrentControlSet.

Though Windows does not necessarily use all the pagefile set, it will
reserve disk space which is then not available to the user for applications
and processes.

You can check how large your system managed page file is on the DISK by
looking for pagefile.sys in the root directory of C:\ and checking the
properties. Sometimes they are quite different to the settings in Control
Panel for Virtual Memory
Uncle John

Thanks for all the replies. I guess I'm puzzled mainly by the fact
that swap file size set goes up linearly with RAM size. Couldn't you
justifiably argue that it should go down? The more RAM you *actually*
have, the less *virtual* RAM you need?

 

[Bob I]

With only 512MB then 1.5 times is reasonable.

 

[R. McCarty]

Paging isn't such an issue as it was just a few years ago. Most PCs
today have 256+ physical memory in them. I have 1.0 Gigabyte of
Dual-Channel DDR and even with "Heavy" loading ( Audio mastering,
Virtual PCs) my pagefile use is almost negligible. However, it's still
a vital/core function of XP (2000, NT = which has it's roots in code
from DEC VMS (Virtual Memory System). I think you'll find in the
future versions of Windows a somewhat modified approach to the
setup/size of Pagefile space. If you are interested in a more "Techie"
explanation of the topic, read the following:
http://www.support.microsoft.com/default.aspx?scid=kb;en-us;555223&SD=tech

 

[Ken Blake]

In

A few years ago there used to be much (sometimes heated)
discussion
about the 'optimum' size of the XP swap file. I vaguely recall
that
the widely-quoted rule of thumb of using 1.5 times the size of
your
RAM was disowned by several experts.

So I was surprised to find that, having recently changed my own
setup
to 'System Managed', that this rule is apparently being used by
the OS
itself. (In my case, with 512 MB, it has reserved 767 MB.)

Is this rule indeed 'respectable' again please?

It never was respectable. Read the late MVP Alex Nichol's article
"Virtual Memory in Windows XP" at
http://www.aumha.org/win5/a/xpvm.htm

 

[Ken Blake]

In

Thanks for all the replies. I guess I'm puzzled mainly by the
fact
that swap file size set goes up linearly with RAM size.
Couldn't you
justifiably argue that it should go down? The more RAM you
*actually*
have, the less *virtual* RAM you need?

Exactly right.

 

[Stan Brown]

A few years ago there used to be much (sometimes heated) discussion
about the 'optimum' size of the XP swap file. I vaguely recall that
the widely-quoted rule of thumb of using 1.5 times the size of your
RAM was disowned by several experts.

Bert Kinney gave what I think is the definitive answer: there's no
hard-and-fast rule. Your best bet is to let Windows manage it and see
how large it actually gets.

The 1.5 times (or 2 times) rule is inherently silly. For a given set
of tasks, the more physical ram you have the _less_ page file space
you would normally need. But again, Win XP does a decent job of
managing that so the best advice is just to let it alone.

--
Stan Brown, Oak Road Systems, Tompkins County, New York, USA
http://OakRoadSystems.com
Fortunately, I live in the United States of America, where we are
gradually coming to understand that nothing we do is ever our
fault, especially if it is really stupid. --Dave Barry

 

[Terry Pinnell]

Bert Kinney gave what I think is the definitive answer: there's no
hard-and-fast rule. Your best bet is to let Windows manage it and see
how large it actually gets.

The 1.5 times (or 2 times) rule is inherently silly. For a given set
of tasks, the more physical ram you have the _less_ page file space
you would normally need. But again, Win XP does a decent job of
managing that so the best advice is just to let it alone.

Thanks a lot for the all the follow-ups. I guess I'll leave it to XP
then!

BTW, I didn't see that 'definitive answer' here from Bert Kinney that
Stan mentioned?

 

[Stan Brown]

BTW, I didn't see that 'definitive answer' here from Bert Kinney that
Stan mentioned?

It wasn't in this thread, but a few weeks ago when I asked the same
question you're asking now.

--
Stan Brown, Oak Road Systems, Tompkins County, New York, USA
http://OakRoadSystems.com
Fortunately, I live in the United States of America, where we are
gradually coming to understand that nothing we do is ever our
fault, especially if it is really stupid. --Dave Barry