Available Physical Memory? means what?

[Ted Jensen]

Windows XP SP1

If I go to Start/All_Programs/System_Tools/System_Information I'm
informed that I have 512 MB Total Physical Memory and 260.10 MB
Available Physical Memory.

How do I interpret this? i.e. what does Available mean in this case?
Does that mean that the rest is in use by the operating system or
what?

Ted-

 

[Guest]

Let's look at few basics.

Your PC has random access memory, or RAM - shown as Total Physical Memory -
being 512Mb.

If you look in Task manager you get more Information, including Page File
and Commit Charge.
The Available Memory parameter:

This parameter shows the latest observed amount of physical memory, in
megabytes, available to processes running on the computer.

Memory Usage parameter

This parameter shows the memory utilization for the monitored Windows
computer.

Memory utilization is the ratio of Memory:Committed Bytes to Memory: Commit
Limit. Committed memory is physical memory in use for which space has been
reserved in the paging file should it need to be written to disk. The commit
limit is determined by the size of the paging file. If the paging file is
enlarged, the commit limit increases, and the ratio is reduced.

The page file is created during the Windows XP installation and resides on
the hard drive. Page files are also measured in megabytes. XP creates a page
file which is 1.5 times the amount of installed RAM. Thus if an application
or process is idle, Windows may move all or part of its code out of RAM and
onto the Hard Drive Paging File.

In your specific case, at that time the computer had applications and
process opened that used 260.10Mb of the 'Available Memory' and yuou would
not expect to see the paging file 'working', that is to say when your demand
for RAM doesn't exceed the Physical Size of Memory, then you will not hear
the information being moved in and out of memeory and onto and off the HDD.

 

[Ted Jensen]

Thanks so much for your response! I think I understand most of it,
but will need time to study it a bit more and research some of the
concepts involved. I'll get back to you if I have more questions.

A couple of questions now:

When I bought the system it came with 256MB of RAM and was
running Win98. I purchased XP when it came out, about a year
later and when I installed it I partitioned the drive to leave Win98
on it so I could switch back and forth between operating systems.
Then, a few month later, I purchased and installed another 256 MB
of RAM.

Should I have increased the size of the paging file at that time?
If it will help, how can I increase its size now? The reason I'm
asking is I am helping a friend who is running XP and upgrading
his system from 128 MB of RAM to 512 MB and I want to advise
him to also change the size of his paging file if that would be
appropriate.

Ted-

 

[frodo]

"Available Memory" is the largest amount of RAM that the OS can give to a
requesting process without resorting to paging to the hard disk. If more
is requested it will have to swap, which slows things down.

It is not the same as "unused memory" or "free memory". A large part of
the "Available Memory" is being used as the disk cache, but if requested
that'll be given over to a process in an instant.

Many people look at the Avail Mem figure and complain that "I paid for 512
MB of RAM and 350 MB of it is available, I should have only gotten 256MB."
They think 350 MB of their RAM is going completely unused. It's being
used, but is available for re-use as required. XP will attempt to "use"
all the RAM available to it, very little of your RAM is actually ever
unused.

 

[Fat Bloke]

"Available Memory" is the largest amount of RAM that the OS can give to a
requesting process without resorting to paging to the hard disk. If more
is requested it will have to swap, which slows things down.

[snip]

What is Virtual Memory? My Brother printer installation CD says it needs 3
Mbyte virtual memory to install. I have 2 Mbyte. How do I increase this -
or do whatever it is I have to do?

TIA.
------------------------------------------------------------

This post did not necessarily reflect my opinions. So there.

Sent from within Forte's Agent.

Pull the pins out to reply direct.

 

[Tim]

It is really easy to change the paging file in Windows XP and i
reccomend you do so. As "bar" said, you need to change the paging file
to 1.5 times the amount of memory you have. To save you the math. The
paging file should be 768 megabytes if you have 512 megabytes of
physical memory. Right click on my computer > properties > advanced >
under perfomance click settings >
advanced > under virtual memory click change > and now you have two
options, you can just let windows manage it (which i would do) or
change the initial size under custom size to 768. I sure hope this
helps your system memory problems.
-Tim

 

[Ted Jensen]

On 26 Aug 2004 07:49:20 -0700, (e-mail address removed) (Tim) wrote:

Thanks Tim! That answered an important part of my question! Ted-