Is there a problem to use WinXP in a 3 GB memory machine?

[Juan I. Cahis]

Dear friends:

Is there a problem to use WinXP in a 3 GB memory machine?

I understand that WinXP doesn't use more memory than 2 GB, but is
there a problem for XP if the machine has 3 GB of main memory,
independently if XP will use the extra memory or not?


Thanks
Juan I. Cahis
Santiago de Chile (South America)
Note: Please forgive me for my bad English, I am trying to improve it!

 

[Tim Slattery]

Dear friends:

Is there a problem to use WinXP in a 3 GB memory machine?

I understand that WinXP doesn't use more memory than 2 GB, but is
there a problem for XP if the machine has 3 GB of main memory,
independently if XP will use the extra memory or not?

Your understanding is not correct. 32-bit WinXP has a 4GB address
space, as does your 32-bit hardware. The hardware has to use some of
that address space to access video memory, BIOS, etc. What's left over
is used to access your RAM. If you install 4GB, you'll probably be
able to use 3 to 3.5GB. If you install 3GB, you will probably be able
to use all of it. See http://members.cox.net/slatteryt/RAM.html

Your 2GB number probably comes from a misunderstanding of Virtual
memory. Each process running in XP is assigned a 4GB virtual memory
space (meaning that each process thinks it has 4GB RAM all to itself).
This is divided half-and-half between the application and the OS. Any
part of this VM space may be in RAM or on the disk at any particular
time. It's the operating system's job to keep track of all this and
have the right part at the right place when it's needed. It will use
all your physical RAM to keep as much of the various VM spaces as
available as possible.

 

[Plato]

Is there a problem to use WinXP in a 3 GB memory machine?

No.

 

[Unknown]

Absolutely not!
Dear friends:

Is there a problem to use WinXP in a 3 GB memory machine?

I understand that WinXP doesn't use more memory than 2 GB, but is
there a problem for XP if the machine has 3 GB of main memory,
independently if XP will use the extra memory or not?


Thanks
Juan I. Cahis
Santiago de Chile (South America)
Note: Please forgive me for my bad English, I am trying to improve it!

 

[Ian D]

Dear friends:

Is there a problem to use WinXP in a 3 GB memory machine?

I understand that WinXP doesn't use more memory than 2 GB, but is
there a problem for XP if the machine has 3 GB of main memory,
independently if XP will use the extra memory or not?


Thanks
Juan I. Cahis
Santiago de Chile (South America)
Note: Please forgive me for my bad English, I am trying to improve it!

There will be no problem with 3GB, and if you have memory intensive
applications it may help. As Tim Slattery described above, XP and
Vista give applications 2GB of virtual address space. The OS gets
the other 2GB. The virtual addresses are mapped into physical RAM
addresses where code and data are stored. If you have 2GB of RAM,
that memory is shared by both the application and the OS. If you
have 3GB, then you have a full 2GB available for the application
with an additional 1GB for the OS. There is a way to give more than
2GB of address space to applications by using the /3GB switch, but
it's a bit technical, and the applications have to be able to use this
switch. If you are interested, Google "/3GB".

 

[LPS-AU]

So just to simplify this for a novice like me.

I have just increased my PC's 1GB of RAM to 3GB (MB can have 4GB installed).
I do a fair bit of Video and photo editing etc. Is there any need to make
any changes or adjustments to my XP Home operating system, to optimise the
use/availability of the increased RAM?

Thanks, LPS-Au
*******************

 

[Ian D]

So just to simplify this for a novice like me.

I have just increased my PC's 1GB of RAM to 3GB (MB can have 4GB
installed). I do a fair bit of Video and photo editing etc. Is there any
need to make any changes or adjustments to my XP Home operating system, to
optimise the use/availability of the increased RAM?

Thanks, LPS-Au
*******************

Probably not. The thing you have to remember is that if you expand the
application virtual address space beyond 2GB, and the application uses that
space, then you are taking the corresponding RAM away from XP. The OS
will still have sufficient virtual addressing space, but may lack physical
RAM to map into. XP's performance will then suffer if it starts paging due
to insufficient RAM. The thing to do is make sure your editing apps are
the only ones running.

 

[Unknown]

No changes required. Everything should be fine.

So just to simplify this for a novice like me.

I have just increased my PC's 1GB of RAM to 3GB (MB can have 4GB
installed). I do a fair bit of Video and photo editing etc. Is there any
need to make any changes or adjustments to my XP Home operating system, to
optimise the use/availability of the increased RAM?

Thanks, LPS-Au
*******************

 

[Tim Slattery]

Probably not. The thing you have to remember is that if you expand the
application virtual address space beyond 2GB, and the application uses that
space, then you are taking the corresponding RAM away from XP. The OS
will still have sufficient virtual addressing space, but may lack physical
RAM to map into. XP's performance will then suffer if it starts paging due
to insufficient RAM. The thing to do is make sure your editing apps are
the only ones running.

This is really confused. Adding more RAM will NOT ever hurt
performance. Each process has a 4GB virtual address space. Each
address space - as well as all physical RAM - is divided into 4KB
pages. Pages for any virtual space can be either in RAM or in the swap
file at any time. For any given VM space, some pages will be on the
swap file and some in RAM at any time. The OS has to keep track of
what's where, and when an app requests a page that's currently on the
swap file, the OS has to decide which page of RAM can be either
discarded or written to the swap file to make room for it.

Obviously then, the more RAM you have, the more pages can be stored in
RAM and the less you will need the swap file. Accessing pages that are
already in RAM is *MUCH* faster than swapping a page out, reading a
new one in, then accessing it.