Windows XP Pro SP2 - 4GB RAM but Windows only shows 3 GB

  • Thread starter Thread starter Michel
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M

Michel

Hi,

I have 2 Dell laptops with same hardawre configuration, 4 GB RAM and Windows
XP Pro SP2.
They have been bought in an interval of one month so BIOS is not exactly at
the same version.
On the oldest one, Windows correctly displays 4GB, for instance in task
manager when the most recent one only displays 3GB.
I precise hat winmsd displays that my RAM is 4 GB in both laptops.

Sorry if it is a FAQ but I didn't find the answer when I searched in this
forum.
Thank you for reading this message and thanks to those that can help to
solve this problem.

Michel
 
Hi,

I have 2 Dell laptops with same hardawre configuration, 4 GB RAM and Windows
XP Pro SP2.
They have been bought in an interval of one month so BIOS is not exactly at
the same version.
On the oldest one, Windows correctly displays 4GB, for instance in task
manager when the most recent one only displays 3GB.
I precise hat winmsd displays that my RAM is 4 GB in both laptops.

Sorry if it is a FAQ but I didn't find the answer when I searched in this
forum.
Thank you for reading this message and thanks to those that can help to
solve this problem.

Michel
Click to expand...

Laptop's usually "share" the installed RAM with the on-board video
card. Check the hardware setting so as to see the video RAM size on
each.
 
Thanks for the answer.
It is exactly the same thing on both laptops (512 MB).
Now after installing the latest updates, the first laptop displays 3584 MB
and the second one 3072 MB.

So the first one 3584+512=4096 should give the correct value but the second
one is off by 512MB. Does it count twice the video memory?
How can I see if video RAM is taken from the installed RAM?

Regards
Michel
 
Michel said:
Hi,

I have 2 Dell laptops with same hardawre configuration, 4 GB RAM and
Windows
XP Pro SP2.
They have been bought in an interval of one month so BIOS is not exactly
at
the same version.
On the oldest one, Windows correctly displays 4GB, for instance in task
manager when the most recent one only displays 3GB.
I precise hat winmsd displays that my RAM is 4 GB in both laptops.

Sorry if it is a FAQ but I didn't find the answer when I searched in this
forum.
Thank you for reading this message and thanks to those that can help to
solve this problem.
Click to expand...

This is probably the most frequently asked question, and I'm surprised you
didn't find the answer, because I think it has been asked about 3 times very
recently.

Windows 32 bit operating systems are limited to a total memory addressing
space of 4 Gb.

In the case of your laptop this most likely comprises:

1. System memory
2. Video memory
3. Input/Output devices

It is this last item that causes the problems because it requires memory
address space to access these devices, which then becomes unavailable to
Windows to address real memory. The practical upshot is that the operating
system can end uop addressing (typically) 3.1 to 3.5 Gb of memory. Your
laptop may well take the video memory out of that as well (depending on the
video system - some do have dedicated memory).

The system information screen usually shows the fitted memory, but utilities
like task manager usually show the actual available memory. The fact that
your two laptops have been bought a month apart may well mean that the
hardware differs in more respects than the BIOS (these things change
unbelievably quickly). Also, the way the plug and play routines actually
allocate the addressing can often change between configurations (and is
rarely contiguous) These may account for differences in the reported memory
or the way in which it is reported.

Unless you are doing something particularly resource hungry (like editing HD
video - though you can't do this with shared video memory), you are unlikely
to notice the difference in available RAM, 3Gb being overkill for most
applications.

I wouldn't loose any sleep over it.
 
Thank you for your post.
I indeed didn't find the answer and I posted this in several forums and you
are the first one to give me a complete answer.

The only difference I see is in BIOS, one is version A05 (01/30/2008) and
the other version A08 (02/28/2008). (Well, hard disks are also different but
I don't think it matters here.)
Both have video NVIDIA Quadro FX 1600M with 512MB memory. I think this is
internal video memory and not shared one (maybe you can confirm this, I
didn't see anything explaining this on NVidia site).
The memory reported by task manager, systeminfo and AIDA32 tool (I don't
know if you know it) are 3584 MB and 3072 MB. BIOS, winmsd and AIDA32 report
4096 MB or 2 banks of 2048 MB, so hardware is correct.

These laptops are for testing Oracle databases of different versions, so I
need all the possible memory. I currently use 2GB machines but this is too
few and I have to stop some databases when I make tests on other ones, and I
can't make some distributed processing tests.

But sure I will not loose sleep over this. :)

Regards
Michel
 
Michel said:
Thank you for your post.
I indeed didn't find the answer and I posted this in several forums and you
are the first one to give me a complete answer.

The only difference I see is in BIOS, one is version A05 (01/30/2008) and
the other version A08 (02/28/2008). (Well, hard disks are also different but
I don't think it matters here.)
Both have video NVIDIA Quadro FX 1600M with 512MB memory. I think this is
internal video memory and not shared one (maybe you can confirm this, I
didn't see anything explaining this on NVidia site).
The memory reported by task manager, systeminfo and AIDA32 tool (I don't
know if you know it) are 3584 MB and 3072 MB. BIOS, winmsd and AIDA32 report
4096 MB or 2 banks of 2048 MB, so hardware is correct.

These laptops are for testing Oracle databases of different versions, so I
need all the possible memory. I currently use 2GB machines but this is too
few and I have to stop some databases when I make tests on other ones, and I
can't make some distributed processing tests.

But sure I will not loose sleep over this. :)

Regards
Michel
Click to expand...

Say that the hardware had both a built-in graphics, as well as a separate
GPU. If the built-in graphics was enabled on one laptop, and disabled on
the other, perhaps that would account for a different allocation of
address space for system busses.

Some info here.

http://support.asus.com/faq/faq_rig...4-D5C9-49C4-5E1B-CF724DB5C000&SLanguage=en-us

And there is a picture here, of an address map on an affected system. The
allocation of additional PCI or PCI Express address space, seems to have
a granularity of 256MB chunks.

http://download.intel.com/support/motherboards/server/sb/ta71902.pdf

Paul
 
Paul said:
Say that the hardware had both a built-in graphics, as well as a separate
GPU. If the built-in graphics was enabled on one laptop, and disabled on
the other, perhaps that would account for a different allocation of
address space for system busses.
Click to expand...

How can I check this?
In both cases winmsd say there are 512MB on video board.

Regards
Michel
 
No difference in BIOS.
Device manager says differences in addresses:
FD000000-FDFFFFFF => F5000000-F5FFFFFF
E0000000-EFFFFFFF => E0000000-EFFFFFFF
FA000000-FBFFFFFF => F2000000-F3FFFFFF

How can I change this?
I really appreciate your help, thanks.
Michel
 
Michel said:
No difference in BIOS.
Device manager says differences in addresses:
FD000000-FDFFFFFF => F5000000-F5FFFFFF
E0000000-EFFFFFFF => E0000000-EFFFFFFF
FA000000-FBFFFFFF => F2000000-F3FFFFFF

How can I change this?
I really appreciate your help, thanks.
Michel
Click to expand...

I don't know if I can find a really good resource that
describes how that stuff works.

When I boot a Linux CD, the very first thing Linux does,
is mention the "E820" BIOS memory map. The BIOS has the
ability to define a memory map, and as far as I know, other
things respect the reservations made. That might include
the setting of the "top of memory" or "top of low memory"
registers in the Northbridge.

I'm not sure that OSes change everything when they start
up.

So what you need to find, is why the BIOS memory map,
is defined the way it is.

There is some mention of E820 here.

http://support.microsoft.com/kb/117373

I don't have a 4GB configuration here, so cannot really
test the limits of my system.

My best guess,
Paul
 
Michel said:
No difference in BIOS.
Device manager says differences in addresses:
FD000000-FDFFFFFF => F5000000-F5FFFFFF
E0000000-EFFFFFFF => E0000000-EFFFFFFF
FA000000-FBFFFFFF => F2000000-F3FFFFFF

How can I change this?
Click to expand...

This is because the addresses have been allocated differently at set up.
Although it is possible to change the allocation, I really wouldn't
recommend it because unless you really really know what you are doing, you
can end up with a non working system. These addresses are high up the
order, and there will almost certainly be something below it so you are
unlikely to make any difference anyway.
 
Michel said:
How can I check this?
In both cases winmsd say there are 512MB on video board.
Click to expand...

Control Panel should have an nVidia utility. Opening that should give you
screen with a 'Properties' or 'Advanced' button that opens to a screen that
shows the video hardware configuration. This should state the video memory
size and whether it's dedicated or shared (but as it's nVidia graphics,
don't be surprised if it's both).
 
M.I.5¾ said:
This is because the addresses have been allocated differently at set up.
Although it is possible to change the allocation, I really wouldn't
recommend it because unless you really really know what you are doing, you
can end up with a non working system. These addresses are high up the
order, and there will almost certainly be something below it so you are
unlikely to make any difference anyway.
Click to expand...

The difference in the addresses is exactly 512MB that is the available
memory I loose.
I think this is because driver or the like are not loaded in the same
sequence.
I'd wish to change the order of components loading in order to get back my
512MB or about this. Do you know where I can find this sequence of loads?

I didn't find anything more with nVidia utility in Control panel. It is more
a configuration program to change number of pixels, colors, and so on,
nothing about memory (in any tab I could open).

Once again I appreciate the time you spend to help me.
Regards
Michel
 
Michel said:
The difference in the addresses is exactly 512MB that is the available
memory I loose.
I think this is because driver or the like are not loaded in the same
sequence.
I'd wish to change the order of components loading in order to get back my
512MB or about this. Do you know where I can find this sequence of loads?
Click to expand...

It is not the sequence of loading that determines the memory allocation. It
is how the plug and pray routine allocated the memory when the hardware was
first installed. Once the allocation has been made, it stays fixed unless
something is installed which requires a reallocation (usually something with
a large allocation requirement). Changing the allocation will only release
the address space if there isn't something occupying an address lower than
your graphics card (and even then, it is allocated in blocks). This is most
likeley, because addresses are invariably allocated well below this address.
This is a reflection of the fact that the video adapter is one of the first
things to be installed.
I didn't find anything more with nVidia utility in Control panel. It is
more
a configuration program to change number of pixels, colors, and so on,
nothing about memory (in any tab I could open).
Click to expand...

My nVidia control panel has a hardware tab, but it is a newer 8600 family
device so yours may differ.
 
M.I.5¾ said:
It is not the sequence of loading that determines the memory allocation. It
is how the plug and pray routine allocated the memory when the hardware was
first installed. Once the allocation has been made, it stays fixed unless
something is installed which requires a reallocation (usually something with
a large allocation requirement). Changing the allocation will only release
the address space if there isn't something occupying an address lower than
your graphics card (and even then, it is allocated in blocks). This is most
likeley, because addresses are invariably allocated well below this address.
This is a reflection of the fact that the video adapter is one of the first
things to be installed.
Click to expand...

Is it possible if I find and deinstall something that is allocated higher in
the memory and then reinstall it, it may be possible memory allocated to
video will change and I may get back my 512MB or a little bit less?

My nVidia control panel has a hardware tab, but it is a newer 8600 family
device so yours may differ.
Click to expand...

I didn't see a "system info" link at the very bottom of nVidia control panel.
It gives me for both:
- ForceWare version : 156.19
- Memory : 512MB (dedicated 256MB)
- Video BIOS version : 60.84.66.00.05
- IRQ : 16
- Bus : PCI Express x16
Then a list of components (DLL) all of the same version (6.14.11.5619)
Do you know what does the "memory" line mean?

Once again your post learned me much.
Michel
 
Ok, now I see it is not possible. I dumped the allocated memory (with the
help of AIDA32, ancestor of Everest that Paul talked about).
It is about the same (a couple of things that switched) but I have one more
line:
Memory C0000000-DFFFFFFF Shared Bus PCI
that kills the 512MB.
I don't know what it is for but I'm pretty sure I can't do anything about it.

Thanks for your valuable help.
Michel
 
Michel said:
Ok, now I see it is not possible. I dumped the allocated memory (with the
help of AIDA32, ancestor of Everest that Paul talked about).
It is about the same (a couple of things that switched) but I have one more
line:
Memory C0000000-DFFFFFFF Shared Bus PCI
that kills the 512MB.
I don't know what it is for but I'm pretty sure I can't do anything about it.

Thanks for your valuable help.
Michel
Click to expand...

I forgot to precise:
E0000000 = 3584MB
C0000000 = 3072MB
Exactly the figures that give task managers and so on.

Michel
 
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