Getting XP Pro to see 4GB of memory

  • Thread starter Thread starter learner
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learner

Just upgraded my Windows XP SP2 box to 4GB of memory. My BIOS sees 4096MB.
I've added the /PAE option to boot.ini but it still says "3.62GB of RAM"
when I look at system properties. what am I missing?

Below is the whole boot.ini:

[boot loader]
timeout=5
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" /PAE /fastdetect /NoExecute=OptIn
C:\CMDCONS\BOOTSECT.DAT="Microsoft Windows Recovery Console" /cmdcons
 
learner said:
Just upgraded my Windows XP SP2 box to 4GB of memory. My BIOS sees
4096MB. I've added the /PAE option to boot.ini but it still says
"3.62GB of RAM" when I look at system properties. what am I missing?

Below is the whole boot.ini:

[boot loader]
timeout=5
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" /PAE /fastdetect /NoExecute=OptIn
C:\CMDCONS\BOOTSECT.DAT="Microsoft Windows Recovery Console"
/cmdcons
Click to expand...

Install Windows XP x64 instead (if you have a 64bit capable system.)
Otherwise - you are getting all you will get out of WIndows XP 32bit.
 
Sun, 30 Dec 2007 07:19:38 -0600 from Bob Peters
Limiting memory. Looks like a rather ugly bug introduced in SP2. I do
hope that SP3 includes a fix for that when and if it ever comes out.
Click to expand...

You might want to read the cited text before commenting.

It's pretty obvious that this code is behaving as Microsoft intended.
 
Bob Peters said:
Limiting memory. Looks like a rather ugly bug introduced in SP2. I do
hope that SP3 includes a fix for that when and if it ever comes out.
Click to expand...

This is by design. It is not a bug.
 
It's not a bug and what you say is also incorrect. There was an
"intentional" change made in SP2 to deliberately limit the available
limit to about 3.2GB. The hardware architecture does not limit memory
addressing, it takes what it needs and the rest of the unused addresses
are available for the installed RAM, prior to SP2 that could be as high
as 3.75GB, it all depends on the hardware installed in the box.

The changes in SP2 were made for compatibility reason with some drivers,
probably because of poorly written drivers if you ask me. In any case I
think that it is a dumb fix, one of these Microsoft dillies! Because
"some" drivers are screwy everybody, whether or not they have screwy
drivers, should be denied the use of potentially available memory above
3.2GB, what a kludge of a fix! Anyway, someone told me in another group
that they have 4GB on XP 32-bit with SP2 and that they are able to see
much more than the 3.2GB limit that was supposedly introduced with SP2
so I don't quite know what to make of this SP2 fix.

John
Not a bug. Hardware architecture limits memory addressing to about 3.2 gig.
Click to expand...
 
Once again you read something into a post and misinterpret. 'The hardware
takes what it needs and the rest of the unused addresses are available for
memory'.
If that doesn't equate to 'hardware architecture limitation' what is it in
your words??
Since all memory is used (not all by programs) I think it to be brilliant
hardware design.
Think of all the hardware address bits saved.
John John said:
It's not a bug and what you say is also incorrect. There was an
"intentional" change made in SP2 to deliberately limit the available limit
to about 3.2GB. The hardware architecture does not limit memory
addressing, it takes what it needs and the rest of the unused addresses
are available for the installed RAM, prior to SP2 that could be as high as
3.75GB, it all depends on the hardware installed in the box.

The changes in SP2 were made for compatibility reason with some drivers,
probably because of poorly written drivers if you ask me. In any case I
think that it is a dumb fix, one of these Microsoft dillies! Because
"some" drivers are screwy everybody, whether or not they have screwy
drivers, should be denied the use of potentially available memory above
3.2GB, what a kludge of a fix! Anyway, someone told me in another group
that they have 4GB on XP 32-bit with SP2 and that they are able to see
much more than the 3.2GB limit that was supposedly introduced with SP2 so
I don't quite know what to make of this SP2 fix.

John
Click to expand...
 
Unknown said:
Not a bug. Hardware architecture limits memory addressing to about 3.2 gig.
Click to expand...

The x86 architecture includes PAE, which expands the address space well
above 4G. Both xp and vista includes a PAE kernel, but limits the
physical address space to 4G anyway
 
No, I did not misinterpret your post. You said:
Hardware architecture limits memory addressing to about 3.2 gig.
Click to expand...

That is incorrect. Implementations in SP2 limits memory addressing to
about 3.2GB, not the hardware architecture. Don't bother with a reply!

John
 
Sun, 30 Dec 2007 10:54:24 -0600 from Xandros
This is by design. It is not a bug.
Click to expand...

The word "misfeature" is useful here -- intended behavior that seems
remarkably ill-chosen.
 
"...intended behavior that seems remarkably ill-chosen."

Sorry I arrived late. Is this discussion about my mother-in-law?
 
jorgen said:
The x86 architecture includes PAE, which expands the address space well
above 4G. Both xp and vista includes a PAE kernel, but limits the
physical address space to 4G anyway
Click to expand...

Not trying to be sarcastic here, but am actually curious:

You shop for a decent new motherboard, you're usually looking at a
capacity for 8G on one that's "Designed for Windows XP" and "Windows
Vista Certified." (at the time I'm writing this)

What's the point if you can only address half of that, max?

Surely the hardware can't require 4G behind the scenes, even if you're
building a monster gaming rig to go gunning for the Angry German Kid in
"Unreal."

Is the higher capability entirely for those early adapters who are going
64-bit even without many goodies yet compatible?
 
learner said:
Just upgraded my Windows XP SP2 box to 4GB of memory. My BIOS sees 4096MB.
I've added the /PAE option to boot.ini but it still says "3.62GB of RAM"
when I look at system properties. what am I missing?
Click to expand...

I'd guess that your hardware doesn't support PAE. Your 32-bit system
has a 4GB address space, but some of that must be used to access video
RAM, BIOS, etc. See http://members.cox.net/slatteryt/RAM.html
 
John John said:
No, I did not misinterpret your post. You said:


That is incorrect. Implementations in SP2 limits memory addressing to
about 3.2GB, not the hardware architecture. Don't bother with a reply!
Click to expand...

That's not true.
 
Tim said:
That's not true.
Click to expand...

Having reread the article I see that the addressing in SP2 is only
limited with the /PAE switch. Without PAE mode usable memory may be
more than 3.12GB.

John
 
Not trying to be sarcastic here, but am actually curious:

You shop for a decent new motherboard, you're usually looking at a
capacity for 8G on one that's "Designed for Windows XP" and "Windows
Vista Certified." (at the time I'm writing this)

What's the point if you can only address half of that, max?

Surely the hardware can't require 4G behind the scenes, even if you're
building a monster gaming rig to go gunning for the Angry German Kid in
"Unreal."

Is the higher capability entirely for those early adapters who are going
64-bit even without many goodies yet compatible?
Click to expand...


Yes. It's for those running 64-bit Windows.

By the way, it would be a very rare occurrence for someone running
32-bit Windows XP to be able to effectively use more than 4GB (or even
3GB), even if the hardware/software supported it. Unless you run
extremely memory-hungry applications, you can't come close to even
using that much.
 
Unknown said:
Not a bug. Hardware architecture limits memory addressing to about 3.2
gig.
Click to expand...
The x86 architecture includes PAE, which expands the address space well
above 4G. Both xp and vista includes a PAE kernel, but limits the physical
address space to 4G anyway> The x86 architecture includes PAE, which
expands the address space well above 4G. Both xp and vista includes a PAE
kernel, but limits the physical address space to 4G anyway
Click to expand...

Bob said:
Not trying to be sarcastic here, but am actually curious:

You shop for a decent new motherboard, you're usually looking at a
capacity for 8G on one that's "Designed for Windows XP" and "Windows
Vista Certified." (at the time I'm writing this)
Click to expand...

Who is the 'you' that you (Bob Peters) is referring to here in the
statement, "... you're usually looking at a capacity for 8G on one ..."?

I know if I am looking for a motherboard/computer for Windows XP, I look for
one with a maximum capacity of 4GB if I plan on running 32bit Windows/etc.
If I might later install something that might use more (VMWare ESX, *nix,
64bit Windows, etc...) I might look for a board that supports more. If I
find a better board that supports a maximum of 256GB of memory for a few
bucks more - but because of the FSB and other features, it is better
overall - sure, I'll blow the extra few dollars - but not because it
supports the extra RAM necessarily - but because it has other features I
want.

You (Bob Peters) seem to imply that the mysterious 'you' referred to will
only look for two things. RAM capacity and OS compatibility. I look at
FSB, CPU type, onboard USB capability, onboard audio, onboard NIC, HDD
controller type/capacity, RAID or not and even the type of casde it will fit
in. I like to get as much as *I* would need for now and 3-5 years in the
future as I can given a price restraint and what I plan on doing with it in
that timeframe.
What's the point if you can only address half of that, max?
Click to expand...

Why'd you (Bob Peters in this case) bother to spec something you did not
need and whether or not it supports it does not mean you have to utilize it.
I bet you have driven cars that will easily go 120MPH or faster... Did you
have to go that fast all the time because the car had that ability? I bet
you've bought a pack of gum, a six-pack of beer or a bag of candy when you
knew only a few would resolve your current craving.
Surely the hardware can't require 4G behind the scenes, even if
you're building a monster gaming rig to go gunning for the Angry
German Kid in "Unreal."
Click to expand...

I do not understand here - are you making the same point I am? What do you
mean, "... the hardware can't require 4G behind the scenes ..."?
Is the higher capability entirely for those early adapters who are
going 64-bit even without many goodies yet compatible?
Click to expand...

It's for anyone who thinks they might need it. Each person is different.
Some may be happy with a 400MHz machine with 128MB memory running Windows XP
(I've seen it and even read about such people in these newsgroups.) Others
may need 1.8GHz with 512MB memory for minimal performance with their office
apps. Others might need 3.0GHz with 1GB memory for their smaller graphical
editing (2D usually.) Others might be better off with the latest AutoDesk
product, Core2Dua 3.0GHz Xeon and 3.5GB memory for their 3D modeling. It
all depends on the 'you' that you (Bob Peters) was referring to.
 
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