How do I configure to take advantage of 4GB of RAM?

[gary431]

I have upgraded to 4GB of RAM and want to know how I have to configure my computer to get the most advantage from this. I have a new Dell with the XP PRO SP2 OS, dual core 2.4 processor, 2 SATA HD's, 2 DVD drives and is 32bit. Thanks in advance.

[redwudz]

I'm not sure what you are asking. A 32 bit OS should be able to access most of 4GB, probably 3.5 or a little more. Windows does a good job of configuring the memory without much help.

How the memory is used is up to the programs using it. Encoding seems to use about 300 - 500 MBs. Some graphics programs like Photoshop can use more, probably because they can hold images in memory for manipulation.

And welcome to our forums.

[gary431]

I was not aware that the OS would automatically configure itself to take full advantage of the upgrade to 4GB of RAM. Thanks. [/u]

[guns1inger]

This is taken from a post here : http://forums.techarena.in/showthread.php?t=790392

Windows XP 32-bit has an addressable limit of 4GB RAM. Put a full 4GB
of RAM in the machine if it supports it. You will not be able to use
the full 4GB because some of the RAM at the Top of Memory address range
must be made available to other hardware. What you will be able to use
depends on what the other hardware needs, don't expect any more than 3.5
GB, it could be anything between 2.75 to 3.5GB. The 4GB RAM address
limit applies to multi-processor machines also.

If the application is "LARGEADDRESSWARE" aware then you may be able to
use 4GB tuning by using the /3GB switch in the boot.ini file. That will
not allow Windows to increase the addressable memory range but it will
limit the operating system to 1GB of memory and allow LARGEADDRESSWARE
applications to use 3GB.

You should also read this : http://members.cox.net/slatteryt/RAM.html

[gary431]

I upgraded because I understood that there would be an increase in performance. In addition memory is very cheap. Corsair 2X1GB sticks, SDRAM DDR2 667 PC2 5300 for $72.95 free S&H from Newegg.

[ntscuser]

You can upload the most commonly used OS routines into memory so that Win XP runs more quickly and the hard drives have less work to do. You can also reduce the paging file from its default size of 1.5x RAM to something less greedy. Even with Photoshop and a memory hungry newsreader I seldom exceed 1GB of peak usage and almost never reach 1.5GB

[JohnnyMalaria]

On 32-bit Windows, 2GB is used exclusively by the kernel (the drivers etc). 2GB max is available for programs. i.e., you'll never get a memory-intensive program to use more than 2GB irrespective of the amount of RAM installed.

There is an exception to this that permits programs to use up to 3GB but the programs must be specially written to do it and the OS has to be configured to support it (via a boot flag). In reality, this often means that only a specially written program can run successfully on a given computer. Often, such programs cause all kinds of stability problems.

64-bit Windows obviously permits much larger amounts of memory for a program to use - as long as it is a 64-bit program. 32-bit programs running on 64-bit Windows still have the 2GB limit.

From a post I made on a different forum:

32-bit Windows can address memory up to a maximum of 2^32 bits = 4GB.
Half that is dedicated to system stuff (unless you use the /3GB switch then it drops to 1GB).

A single program can use up to 2GB though it will be slight less in reality due to other programs running. But, that 2GB is shared by all programs. i.e., you cannot have one program take 1.8GB and another take 1.8GB as well.

These memory limits have existed ever since MS shipped their first 32-bit apps in the early 90s. But, back then, even 8MB of RAM was an expensive luxury. The concept of a program taking that much, let alone 100s of MB, was hard to imagine. To manage multiple programs running on a system with a small amount of RAM, the OS uses a file on disk to extend the amount of memory available to programs and the system - i.e., the paging file (virtual memory file). In principle, this can grow as large as the maximum address the OS can use - i.e., 4GB. So, running a number of 4MB apps on a 8MB system is very viable - the ones not in use get written to the paging file. However, if enough apps run together, then the paging file can fill up. At that point, the system reports that it has run out of memory. If the paging file is already the biggest it can be, that's a big problem. However, filling up a 4GB paging file with 1000 4MB apps is very unlikely to occur.

Moving forward to today, we can easily afford to fit our computers with 4GB - the maximum usable with 32-bit Windows. If one greedy app gobbles up most of the memory (e.g., CS3) and another large app comes along, the system has to write the first one to the paging file (which will be horribly slow) and, if the second program wants a big chunk of memory that exceeds the total amount available (not just physically but virtually), you get an out-of-memory error. Alternatively, the system can start swapping bits and pieces in and out of the paging file and, being stressed to the max, things can start crashing etc.

[Midzuki]

@ Johnny Malaria: thanks for VERY-well~informing us ^_^

However, there is something that has not changed since the glorious days of
Windows 4.xx (aka "95"): the Win32 OSs are terrible at managing the use of the
RAM. For example, in Windows 95 SP0 it was common to occur a false
"insufficient memory" warning while running Notepad alone; to-day, Windows Explorer
version XP does not allow me to delete a media file because it "believes" the application with which I opened and closed that file is still running and playing the file! Most times I simply call cmd.exe and manage to fool the OS that fooled itself, but there are times when
I really need to do a hard reboot in order to delete files. By last, let's not forget how
weak Windows is at closing non-responsive applications; sometimes,
even the Unix-born kill.exe is not allowed to work :-(

=====

[gary431]

Thanks to you all for all of your helpful responses.

[KBeee]

Also got to remember that whatever size grafix card you've got will lose you that amount of memory above 3GB. If you've got a 500MB video card, you'll have (at most) 3.5GB of system memory available if you're using a 32bit OS.
Get a "I've-Got-More-Money-Than-Sense" 1GB card, or 2 X 0.5GB cards and your 4GB is suddenly 3GB