Page File Size & Location

[Jim]

The Question: What size should I make for my page file, and where should the
page file be located?

The Details: I am installing a new 100GB, 7200RPM Hitachi hard drive in a
Toshiba laptop. I'll be using the Toshiba Recovery DVD, and then installing
all the Microsoft updates using a high-speed broadband connection. The
computer has 2GB of SDRAM already installed and tested satisfactory. I have
also updated the BIOS to the most recent available from the Toshiba web site.

The Background: From various web sites, it seems my page file should be 1.5
to 3.0 times the total amount of RAM. 1.5 plus 3.0 equals 4.5 and 4.5 times
20000 (MB of RAM) equals 90000MB, or 9GB for the page file. Can anyone
confirm this?

Also, the laptop only has room for one hard drive. It seems smart to put
the page file on another partition, but is this safe to do, or will doing
that slow down the computer? If I do put the page file on a separate
partition, can partitions 9GB in size be created? (I'm probably going to be
using FDISK.)

Thanks!

Jim

 

[Ron Martell]

The Question: What size should I make for my page file, and where should the
page file be located?

With only one physical hard drive the page file should be in the same
partition as the operating system.

Creating a separate partition for the page file means that every time
the page file is accessed (read or write) the hard drive head
mechanism has to reposition itself to the page file partition and then
back to the operating system/application program/data partition. This
will slow down overall performance if there is a substantial amount of
actual page file usage.

If you want to make changes to the existing partition structure of a
hard drive, do not use FDISK as it only makes destructive changes
(changing an existing partition destroys the content). You need a
third party partitioning utility such as Partition Magic or BootItNG.


Good luck

Ron Martell Duncan B.C. Canada
--
Microsoft MVP (1997 - 2008)
On-Line Help Computer Service
http://onlinehelp.bc.ca

"Anyone who thinks that they are too small to make a difference
has never been in bed with a mosquito."

 

[Ken Blake, MVP]

The Question: What size should I make for my page file,

For most people, it's best to leave the Windows defaults alone. You
can save some disk space by changing them, but you won't improve
performance (and might hurt it). Since the amount of disk space you
can save is worth only a few pennies in these days of very cheap hard
drives, it usually isn't worth fooling around with.

and where should the
page file be located?

Almost certainly on C:

The Background: From various web sites, it seems my page file should be 1.5
to 3.0 times the total amount of RAM. 1.5 plus 3.0 equals 4.5 and 4.5 times
20000 (MB of RAM) equals 90000MB, or 9GB for the page file. Can anyone
confirm this?

It's wrong. All recommendations based on some multiple of the amount
of RAM you have are wrong. The page file substitutes for RAM, so the
more RAM you have, the *less* page file you need. If you change
anything, you should make the starting value *smaller*, but as I said
above, it's not worth doing.

Also, the laptop only has room for one hard drive. It seems smart to put
the page file on another partition,

No, it's not. Putting the Page File on a second partition is not a
good idea, and can hurt your performance. What it does is move the
page file to a location on the hard drive distant from the other
frequently-used data on the drive. The result is that every time
Windows needs to use the page file, the time to get to it and back
from it is increased. Head movement is the slowest aspect of using the
page file.

Putting the page file on a second *physical* drive is a good idea,
since it decreases head movement, but not to a second partition on a
single drive. A good rule of thumb is that the page file should be on
the most-used partition of the least-used physical drive. For almost
everyone with a single drive, that's C:.

If you have enough RAM, the penalty for moving the page file to a
second partition may be slight, since you won't use the page file
much, but it won't help you. You said you have 2GB of RAM, which is
already more than most people running XP can make effective use of;
you probably hardly ever use the page file, so all of this is
academic, and any changes you make will have next to zero effect.

Also, the other problem with a separate partition like this is that
you run the risk of making it too small, in which case programs will
fail for lack of virtual memory, or too large, which is wasteful of
disk space. If you leave it on C:, it can expand or contract as
needed.

but is this safe to do, or will doing
that slow down the computer?

Yes, it will slow it down. See above.

For more information on this, read this excellent article by the late
MVP, Alex Nichol: "Virtual Memory in Windows XP" at
http://aumha.org/win5/a/xpvm.htm