4GB of RAM installed 3GB shown by WinXP Pro (non64)

[mircea]

OK This is what I have:
Windows XP Pro (non 64)
AMD X2 4400+ - latest driver from them
Patriot 2x 2GB Kit = 4GB RAM on
A8N-SLI Deluxe mob - BIOS 1015 (downloading 1016)
it sees 4GB of RAM OK.
with a nForce 4 SLI (duh) chipset driver v6.70

I have added the line /3GB in the Boot .ini as shown here by microsoft. Here is the boot .ini info:

[boot loader] timeout=10
default=multi(0)disk(0)rdisk(0)partition(1)\WINDOWS
[operating systems]
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Professional" /3GB /noexecute=optin /fastdetect /usepmtimer

Bios sees 4GB of memory
CPUz 1.32 sees 4 GB of memory
But Windows displays only 3.00GB

I want to know if
a) the system will use the 4GB but disply only as 3GB
b) I can't use more than 3GB
c) there's still something else I have to do to properly display and use all 4GB of RAM

As the name shows I went for cheap RAM cuz I don't need huge performance but I use VST programs and some intensive video editing and this will help me a lot.

 

[mechBgon]

From Asus's FAQs for your board:

I have install total 4GB memory on my motherboard. However, it can only recognize around 3.1GB or less. My friend's SLI board even less than 3GB. What's up? How should I do to recognize 4GB totally?

If you installed total 4GB memory, the system will detect less than 4GB of total memory because of address space allocation for other critical functions, such as:

- System BIOS (including motherboard, add-on cards, etc..)
- Motherboards resources
- Memory mapped I/O
- configuration for AGP/PCI-Ex/PCI
- Other memory allocations for PCI devices

Different onboard devices and different add-on cards (devices) will result of different total memory size.
e.g. more PCI cards installed will require more memory resources, resulting of less memory free for other uses.

On a SLI system, since PCI-Ex graphic cards will occupy around 256MB, another 256MB will be occupied after you install a 2nd PCI-Ex graphic card. Hence, 2.75GB memory left only if two SLI cards installed on A8N-SLI Premium while 3.0GB memory left with one graphic card without other add-on devices.


This limitation applies to most chipsets & Windows XP 32-bit version operating system.

If you install Windows XP 32-bit version operating system, we recommend that you install less than 3GB of total memory. If more than 3GB memory is required for your system, then below two conditions must be met:

1. The memory controller which supports memory swap functionality is used. The latest chipsets like Intel 975X, 955X, Nvidia NF4 SLI Intel Edition, Nvidia NF4 SLI X16, and AMD K8 CPU architecture can support the memory swap function.
2. Windows XP Pro X64 Ed. (64-bit) or other OS which can address more than 4GB memory.

You can check below URLs for reference:
http://dlsvr01.asus.com/pub/ASUS/mb/4GB_Rev1.pdf
http://www.intel.com/support/motherboards/server/sb/cs-016594.htm

 

[mircea]

I've read that too. English is not my native language and could not make the end of it. Why when I installed 3 GB on the same systme it showed 3GB and didn't substract the RAM taken by other components but it did so when I installed the last one.
Also this is from the link on Microsoft's page

The maximum amount of memory that can be supported on Windows XP Professional and Windows Server 2003 is also 4 GB

In the end I wasn't sure if WinXP 32 can use 4GB or not. That's what I want to know. Should I take it out and stay on 2-3GB until I get XP64 or Vista.

 

[Fern]

Originally posted by: mechBgon
From Asus's FAQs for your board:


If you installed total 4GB memory, the system will detect less than 4GB of total memory

Hey Mech,

I found this very confusing.

Firstly, when Asus is referring to "the system" are they talking about the mobo, or winXP?

I was thinking that when the system boots up, the ram count would show the 4gigs on the BIOS screen. But the Asus statement makes me think it would not?

I don't use winXP, but am surprised to see it shows the wrong amount?

 

[mechBgon]

Originally posted by: Fern

Originally posted by: mechBgon
From Asus's FAQs for your board:


If you installed total 4GB memory, the system will detect less than 4GB of total memory

Hey Mech,

I found this very confusing.

Firstly, when Asus is referring to "the system" are they talking about the mobo, or winXP?

I was thinking that when the system boots up, the ram count would show the 4gigs on the BIOS screen. But the Asus statement makes me think it would not?

I don't use winXP, but am surprised to see it shows the wrong amount?

I don't really understand it. 😕 Peter would be a good guy to answer this, he's a BIOS engineer. But it appears that if we want to use more than 3GB of RAM, we should use both a 64-bit operating system and a motherboard whose chipset can do that "memory swap functionality" trick that they mention (such as the Asus A8N32-SLI Deluxe).

 

[xtknight]

From a MaximumPC excerpt I read on this, the later addresses in memory are reserved for devices. I read that you can try changing the memory range resources for the devices but that they would be very likely to crash. The solution would be to use a 64-bit OS (memory swap too I guess but I heard nothing about that in MaxPC). PAE (physical address extension) is needed too, but the A64 and P4 (64-bit versions) have that. I think memory swap means that the memory controller maps the devices' memory addresses to the boundary of 64-bit so that you can use up to 2^64 bytes (17179869184 gigs) of RAM minus that little 512 MB on your SLI setup. 🙂

 

[mircea]

I guess I'll wait for Vista before I plug in all 4 sticks. I think it's WinXP fault and not the board. In the BIOS I can see all 4 GB and I can enableboth software and hardware swap functionality for 4 or more GB of RAM.
Microsoft should be more clear on what is WinXP limit.
Has anyone got more than 3GB on a 32bit WinXP???

 

[Rilex]

This is a limitation with 32bit processors and the chipset, not the Operating System's fault (it will occur on other OSes as well).

Why do you expect Vista to change this? And yes, 32bit Windows supports 4GB RAM. Just much of that is reserved by devices on the system.

If absolutely need 4GB RAM to appear in Windows, you'll need to move to a 64bit system.

 

[mircea]

Did you read the first post?? and my last one??
The CPU is a AMD64 4400+ and the MOB is a nForce4-SLI chipset Asus A8N-SLI Deluxe. It's BIOS let's me enable the memory swap. So how could it be a CPU/chipset problem in my case?
Also why is the system reporting full 1/2/3GB when 1/2/3 stiks are in but report only 3GB when 4 sticks are in. Is it alocating resources for other devices only past 3GB??? I have a 6600GT 128 MB where is the rest of the 1GB I don't see.

Again it might be some limitations of WinXP in combination with my hardware and that's why I'm asking here, to pinpoint the problem, hoping to get answers from those that use 4GB of RAM or tried to on systems close to mine.

And yes, Vista will solve this since I will be using the 64 bit version.

 

[JDMnAR1]

The Microsoft documentation is rather ambiguous at best, but you might try the /3GB and /PAE switches in your boot.ini file. I know in Windows Server 2003 they allow the OS to address more than 3GB of RAM, but not certain with XP Pro.

http://support.microsoft.com/kb/833721/en-us

 

[mechBgon]

mircea, if you have any extra hard drives lying around and want to go on a fact-finding mission, you could unplug your normal boot drive, hook up a spare drive, and install a 180-day trial version of WinXP x64 Edition to see whether it can "see" all of the 4GB. That would be interesting. The trialware is available from Microsoft's site for free download.

 

[Rilex]

Originally posted by: mircea
Did you read the first post?? and my last one??
The CPU is a AMD64 4400+ and the MOB is a nForce4-SLI chipset Asus A8N-SLI Deluxe. It's BIOS let's me enable the memory swap. So how could it be a CPU/chipset problem in my case?

You're quite offensive for someone who is asking for help.

The memory swap function will not completely solve this issue. However, I did not see that option in your BIOS manual (not saying it isn't there, but the manual specifically states that 4GB may not be visible and lacking a mention of a work-around).

Also why is the system reporting full 1/2/3GB when 1/2/3 stiks are in but report only 3GB when 4 sticks are in. Is it alocating resources for other devices only past 3GB???

Correct. This is how PCI works in a 32bit environment. You're limited by these, but not limited to, components:
Firmware Hub (BIOS)
Local APIC
PCI Enumeration Area (may be more than one)
PCI Express Area
Video card memory

The more devices you have, the more memory falls.

Again it might be some limitations of WinXP

It is a limitation of any 32bit operating system and x86-32.

And yes, Vista will solve this since I will be using the 64 bit version.

Well, Vista 32bit will not solve this issue ... but you were not clear on how Vista would solve it.

The Microsoft documentation is rather ambiguous at best, but you might try the /3GB and /PAE switches in your boot.ini file.

/3GB is not the way to "solve" this issue. The /3GB switch has no correlation to the amount of installed physical memory (you can use it with 1GB or 2GB RAM for instance, and is highly recommended if running Exchange), rather it has to do with Virtual Address Space (standard being 4GB per app, 2GB allocated to the application, 2GB to the system -- the /3GB switch provides 3GB to the application and 1GB to the system). This is on a per-application basis.

/PAE allows supported versions of Windows to see more than 4GB RAM on 32bit systems. It is also used for the NX bit (NoExecute).

I know in Windows Server 2003 they allow the OS to address more than 3GB of RAM, but not certain with XP Pro.

All consumer versions of Windows support 4GB RAM.

 

[mircea]

Thank you for the explanations.
I'm sorry I sounded agresive on my previos post. It just seemed you gave a quick look and answer.
From what I know Vista will come as a 32/64 installer, and depending on hardware it will install acordingly. Even if I have to choose the Vista 64 is the obviouse solution since the app I use will greatly benefit from this (audio and video editing). I can't wait to see what hapens when they develop native 64 code for the programs.

The BIOS manual??? 😀 Never looked in it. At the end of the DRAM settings there are two enable/disable options for S/W and H/W memory swaping.

I have an old beta of XP64 that won't activate anymore. Is the trial still available even though XP64 is now released for some time??

 

[mircea]

Just got XP64 on and I clearly see 4.00 GB of RAM.

So is it WinXP32 on my hardware?? Or what? Hardware alone seems OK and in 64bit no prob. In 32 bit...

 

[stevty2889]

Originally posted by: mircea
Just got XP64 on and I clearly see 4.00 GB of RAM.

So is it WinXP32 on my hardware?? Or what? Hardware alone seems OK and in 64bit no prob. In 32 bit...

32bit windows will not recognize a full 4gb of ram period, it's not your hardware, it's a limitation of 32bit windows.

 

[ChonChon]

actually....i think if you have PRO and u upgrade to SP2 this problem is supposed to fixed, however dont completely quote me on this one.

 

[stevty2889]

Originally posted by: ChonChon
actually....i think if you have PRO and u upgrade to SP2 this problem is supposed to fixed, however dont completely quote me on this one.

nope, it's a 32bit windows limitation, nothing a service pack can "fix"

 

[Rilex]

Originally posted by: mircea
Just got XP64 on and I clearly see 4.00 GB of RAM.

So is it WinXP32 on my hardware?? Or what? Hardware alone seems OK and in 64bit no prob. In 32 bit...

Windows 32bit can only see (and does see) 4GB RAM, but because of certain allocations which are done near the 4GB barrier (in a 32bit environment), you "lose" RAM (600 - 1GB, and sometimes more) so the system will report 3.4GB or less.

Since Windows 64bit doesn't have the 4GB limitation, you see all 4GB of RAM within Windows.

 

[Avus]

my questions are...
1) since a 32-bit windows OS can only "use" 3GB of RAM even if 4GB installed, is it mean there is no advantage to install 4GB RAM install instead of 3GB??

2) from what i know so far after read this thread, windows "use" some of the RAM for hardware devices. but why i don't see "less" RAM in windows when i put 3GB or less of RAM?

Thanks in advance...

 

[Green Man]

Originally posted by: Avus
my questions are...
1) since a 32-bit windows OS can only "use" 3GB of RAM even if 4GB installed, is it mean there is no advantage to install 4GB RAM install instead of 3GB??

2) from what i know so far after read this thread, windows "use" some of the RAM for hardware devices. but why i don't see "less" RAM in windows when i put 3GB or less of RAM?

Thanks in advance...

It's not because some hardware uses some RAM, it's because some hardware uses some addresses. Now, those addresses aren't available to assign to RAM.
The 4GB RAM limitation is due to a finite number of memory addresses available.

 

[daveybrat]

The easiest answer is to simply buy XP PRO 64-Bit edition or wait several months for the 64-Bit edition of Vista. 😉

 

[Rubycon]

This is rather confusing.

On a E7505 based workstation with 4GB RAM WinXP Pro definitely saw the 4GB. It did take some modifications to get it to work however certain applications (using sound and video editing) became very unstable and crashed. Possible address resource collisions?