4 GB Memory not Recognised

On Windows Server 2003 x64bit OS with 3GB memory - 2x 1GB and 2 x 512MB.

I replaced the 2 x 512MB with 2 x 1GB, therefore the system now has 4 x 1GB
= total 4GB. The bios see it as 4GB but Windows x64bit see it as 3.5 GB.
When I put them in pairs, both pairs in Windows report 2GB but when I place
all 4 it reports 3.5. Hope that explanation makes sense.

Do I need to place the /3GB /PAE switch in the boot.ini?
I thought the x64bit sorted out the memory allocation issue?
Have you seen this before?
Do you think itâ??s a memory, PC H/W or a Server x64bit issue?

Thanks in advance.

Regards,

Firdous

John
Mon Oct 16 10:16:44 CDT 2006

Part of the memory is reserved for the PCI bus unless the BIOS setting is
changed when needed. If you provide your board or BIOS name, someone can
help you find the adjustment you need to make.

"FG" <FG@discussions.microsoft.com> wrote in message
news:49B7336A-A36B-4DF2-9785-0C4C3D05A3DC@microsoft.com...
> On Windows Server 2003 x64bit OS with 3GB memory - 2x 1GB and 2 x 512MB.
>
> I replaced the 2 x 512MB with 2 x 1GB, therefore the system now has 4 x
> 1GB
> = total 4GB. The bios see it as 4GB but Windows x64bit see it as 3.5 GB.
> When I put them in pairs, both pairs in Windows report 2GB but when I
> place
> all 4 it reports 3.5. Hope that explanation makes sense.
>
> Do I need to place the /3GB /PAE switch in the boot.ini?
> I thought the x64bit sorted out the memory allocation issue?
> Have you seen this before?
> Do you think it's a memory, PC H/W or a Server x64bit issue?
>
> Thanks in advance.
>
> Regards,
>
> Firdous
>

Charlie
Mon Oct 16 10:16:33 CDT 2006

What you're seeing is an artifact of the way the 4GB of memory space that
32-bit OSs see is handled. While your bios knows there is 4GB there, it then
goes ahead and reserves some space for the BIOSs of PCI cards, thus
blocking access to some of your 4GB. Now good BIOSs then take and shift the
address of the hidden RAM up above 4GB, making it accessible again for 64bit
OSs. There's usually a switch somewhere in the BIOS to enable that feature.
(Look for something about memory mapping, for example.)

The short answer is, if the BIOS doesn't remap the memory, Windows can't
find it, and you'll only see the 3.5. If you were to then add more memory
beyond 4GB, assuming your mobo supported >4GB, then you'd start to see the
additional memory again.

--
Charlie.
http://msmvps.com/xperts64


"FG" <FG@discussions.microsoft.com> wrote in message
news:49B7336A-A36B-4DF2-9785-0C4C3D05A3DC@microsoft.com...
> On Windows Server 2003 x64bit OS with 3GB memory - 2x 1GB and 2 x 512MB.
>
> I replaced the 2 x 512MB with 2 x 1GB, therefore the system now has 4 x
> 1GB
> = total 4GB. The bios see it as 4GB but Windows x64bit see it as 3.5 GB.
> When I put them in pairs, both pairs in Windows report 2GB but when I
> place
> all 4 it reports 3.5. Hope that explanation makes sense.
>
> Do I need to place the /3GB /PAE switch in the boot.ini?
> I thought the x64bit sorted out the memory allocation issue?
> Have you seen this before?
> Do you think itâ??s a memory, PC H/W or a Server x64bit issue?
>
> Thanks in advance.
>
> Regards,
>
> Firdous
>

Nut
Mon Oct 16 10:41:02 CDT 2006

One of the things you can do to get some of your memory back is to go into
the registry, and set the HotAddMemorySupport bit off. This is enabled by
default with SP1, and should really be turned off if your system doesnt
support HotAdd memory, or even if you dont plan on using it. There is a Q/KB
on the MS support site about this. I learned about this by running the
Exchange Best Practice Analyser against my exchange boxes. It gave us a
larger memory page pool set, and returned about 200MB of ram to the system.

- NuTs

"FG" <FG@discussions.microsoft.com> wrote in message
news:49B7336A-A36B-4DF2-9785-0C4C3D05A3DC@microsoft.com...
> On Windows Server 2003 x64bit OS with 3GB memory - 2x 1GB and 2 x 512MB.
>
> I replaced the 2 x 512MB with 2 x 1GB, therefore the system now has 4 x
> 1GB
> = total 4GB. The bios see it as 4GB but Windows x64bit see it as 3.5 GB.
> When I put them in pairs, both pairs in Windows report 2GB but when I
> place
> all 4 it reports 3.5. Hope that explanation makes sense.
>
> Do I need to place the /3GB /PAE switch in the boot.ini?
> I thought the x64bit sorted out the memory allocation issue?
> Have you seen this before?
> Do you think it's a memory, PC H/W or a Server x64bit issue?
>
> Thanks in advance.
>
> Regards,
>
> Firdous
>

JM
Mon Oct 16 11:50:14 CDT 2006

Bios: Memory Remaping: Enabled or Disabled?

--
Jose Manuel Tella Llop
MVP - Windows
jmtella@XXXcompuserve.com (quitar XXX)
http://www.multingles.net/jmt.htm
news://jmtella.com

Este mensaje se proporciona "como está" sin garantías de ninguna clase,y no
otorga ningún derecho.

This posting is provided "AS IS" with no warranties, and confers no rights.
You assume all risk for your use.



"FG" <FG@discussions.microsoft.com> wrote in message
news:49B7336A-A36B-4DF2-9785-0C4C3D05A3DC@microsoft.com...
> On Windows Server 2003 x64bit OS with 3GB memory - 2x 1GB and 2 x 512MB.
>
> I replaced the 2 x 512MB with 2 x 1GB, therefore the system now has 4 x
> 1GB
> = total 4GB. The bios see it as 4GB but Windows x64bit see it as 3.5 GB.
> When I put them in pairs, both pairs in Windows report 2GB but when I
> place
> all 4 it reports 3.5. Hope that explanation makes sense.
>
> Do I need to place the /3GB /PAE switch in the boot.ini?
> I thought the x64bit sorted out the memory allocation issue?
> Have you seen this before?
> Do you think itâ??s a memory, PC H/W or a Server x64bit issue?
>
> Thanks in advance.
>
> Regards,
>
> Firdous
>

Firdous
Mon Oct 16 14:23:32 CDT 2006

Thanks Guys for your response,

Dell Dimension 9150 - I had a look through the BIOS after updating it to the
latest version A06 and I cannot find this setting.

Any one know if this is supported on this system?

Regards,

Firdous

"JM Tella Llop [MVP Windows]" <jmtella@XXXmvps.org> wrote in message
news:5A082DE0-C9DF-4339-8D5E-844DC4C495F6@microsoft.com...
> Bios: Memory Remaping: Enabled or Disabled?
>
> --
> Jose Manuel Tella Llop
> MVP - Windows
> jmtella@XXXcompuserve.com (quitar XXX)
> http://www.multingles.net/jmt.htm
> news://jmtella.com
>
> Este mensaje se proporciona "como está" sin garantías de ninguna clase,y
> no otorga ningún derecho.
>
> This posting is provided "AS IS" with no warranties, and confers no
> rights.
> You assume all risk for your use.
>
>
>
> "FG" <FG@discussions.microsoft.com> wrote in message
> news:49B7336A-A36B-4DF2-9785-0C4C3D05A3DC@microsoft.com...
>> On Windows Server 2003 x64bit OS with 3GB memory - 2x 1GB and 2 x 512MB.
>>
>> I replaced the 2 x 512MB with 2 x 1GB, therefore the system now has 4 x
>> 1GB
>> = total 4GB. The bios see it as 4GB but Windows x64bit see it as 3.5 GB.
>> When I put them in pairs, both pairs in Windows report 2GB but when I
>> place
>> all 4 it reports 3.5. Hope that explanation makes sense.
>>
>> Do I need to place the /3GB /PAE switch in the boot.ini?
>> I thought the x64bit sorted out the memory allocation issue?
>> Have you seen this before?
>> Do you think it's a memory, PC H/W or a Server x64bit issue?
>>
>> Thanks in advance.
>>
>> Regards,
>>
>> Firdous
>>
>

Charlie
Tue Oct 17 01:53:50 CDT 2006

Sorry, but I don't buy Dells, so can't help there. You could try contacting
Dell directly? It might get a response.

--
Charlie.
http://msmvps.com/xperts64


"Firdous Gangat" <firdousg@hotmail.com> wrote in message
news:OIglWiV8GHA.4996@TK2MSFTNGP03.phx.gbl...
> Thanks Guys for your response,
>
> Dell Dimension 9150 - I had a look through the BIOS after updating it to
> the latest version A06 and I cannot find this setting.
>
> Any one know if this is supported on this system?
>
> Regards,
>
> Firdous
>
> "JM Tella Llop [MVP Windows]" <jmtella@XXXmvps.org> wrote in message
> news:5A082DE0-C9DF-4339-8D5E-844DC4C495F6@microsoft.com...
>> Bios: Memory Remaping: Enabled or Disabled?
>>
>> --
>> Jose Manuel Tella Llop
>> MVP - Windows
>> jmtella@XXXcompuserve.com (quitar XXX)
>> http://www.multingles.net/jmt.htm
>> news://jmtella.com
>>
>> Este mensaje se proporciona "como está" sin garantías de ninguna clase,y
>> no otorga ningún derecho.
>>
>> This posting is provided "AS IS" with no warranties, and confers no
>> rights.
>> You assume all risk for your use.
>>
>>
>>
>> "FG" <FG@discussions.microsoft.com> wrote in message
>> news:49B7336A-A36B-4DF2-9785-0C4C3D05A3DC@microsoft.com...
>>> On Windows Server 2003 x64bit OS with 3GB memory - 2x 1GB and 2 x
>>> 512MB.
>>>
>>> I replaced the 2 x 512MB with 2 x 1GB, therefore the system now has 4 x
>>> 1GB
>>> = total 4GB. The bios see it as 4GB but Windows x64bit see it as 3.5 GB.
>>> When I put them in pairs, both pairs in Windows report 2GB but when I
>>> place
>>> all 4 it reports 3.5. Hope that explanation makes sense.
>>>
>>> Do I need to place the /3GB /PAE switch in the boot.ini?
>>> I thought the x64bit sorted out the memory allocation issue?
>>> Have you seen this before?
>>> Do you think it's a memory, PC H/W or a Server x64bit issue?
>>>
>>> Thanks in advance.
>>>
>>> Regards,
>>>
>>> Firdous
>>>
>>
>
>

Kahasm
Sat Oct 21 03:56:01 CDT 2006

ive got a similar problem here vs 4gb memory; mobo is asus a8n32sli delux; OS
is winXP 64 bit version; ram is corsair XMS 3200 (2x2gb pairs) all are same
model and size

upon boot up, i see 4gb recognised by bios, but after post, it shows 3gb
available, and upon windows boot, in system it only shows 2gb available;

ive tried swapping the sticks around, its all brand new, just built the
system last night (10-20-06)

any ideas?

"Charlie Russel - MVP" wrote:

> Sorry, but I don't buy Dells, so can't help there. You could try contacting
> Dell directly? It might get a response.
>
> --
> Charlie.
> http://msmvps.com/xperts64
>
>
> "Firdous Gangat" <firdousg@hotmail.com> wrote in message
> news:OIglWiV8GHA.4996@TK2MSFTNGP03.phx.gbl...
> > Thanks Guys for your response,
> >
> > Dell Dimension 9150 - I had a look through the BIOS after updating it to
> > the latest version A06 and I cannot find this setting.
> >
> > Any one know if this is supported on this system?
> >
> > Regards,
> >
> > Firdous
> >
> > "JM Tella Llop [MVP Windows]" <jmtella@XXXmvps.org> wrote in message
> > news:5A082DE0-C9DF-4339-8D5E-844DC4C495F6@microsoft.com...
> >> Bios: Memory Remaping: Enabled or Disabled?
> >>
> >> --
> >> Jose Manuel Tella Llop
> >> MVP - Windows
> >> jmtella@XXXcompuserve.com (quitar XXX)
> >> http://www.multingles.net/jmt.htm
> >> news://jmtella.com
> >>
> >> Este mensaje se proporciona "como est" sin garantas de ninguna clase,y
> >> no otorga ningn derecho.
> >>
> >> This posting is provided "AS IS" with no warranties, and confers no
> >> rights.
> >> You assume all risk for your use.
> >>
> >>
> >>
> >> "FG" <FG@discussions.microsoft.com> wrote in message
> >> news:49B7336A-A36B-4DF2-9785-0C4C3D05A3DC@microsoft.com...
> >>> On Windows Server 2003 x64bit OS with 3GB memory - 2x 1GB and 2 x
> >>> 512MB.
> >>>
> >>> I replaced the 2 x 512MB with 2 x 1GB, therefore the system now has 4 x
> >>> 1GB
> >>> = total 4GB. The bios see it as 4GB but Windows x64bit see it as 3.5 GB.
> >>> When I put them in pairs, both pairs in Windows report 2GB but when I
> >>> place
> >>> all 4 it reports 3.5. Hope that explanation makes sense.
> >>>
> >>> Do I need to place the /3GB /PAE switch in the boot.ini?
> >>> I thought the x64bit sorted out the memory allocation issue?
> >>> Have you seen this before?
> >>> Do you think it's a memory, PC H/W or a Server x64bit issue?
> >>>
> >>> Thanks in advance.
> >>>
> >>> Regards,
> >>>
> >>> Firdous
> >>>
> >>
> >
> >
>

Dennis
Sat Oct 21 09:44:26 CDT 2006

Kahasm:
Verify that the bios is setup properly for for 4G remapping. It's
under advanced, CPU configuration, DRAM configuration, s/w DRAM over 4G
remapping and h/w DRAM over 4G remapping, both should be enabled.


"Kahasm" <Kahasm@discussions.microsoft.com> wrote in message
news:D7776983-0280-4B21-8A72-06BD21C6A123@microsoft.com...
> ive got a similar problem here vs 4gb memory; mobo is asus a8n32sli delux;
> OS
> is winXP 64 bit version; ram is corsair XMS 3200 (2x2gb pairs) all are
> same
> model and size
>
> upon boot up, i see 4gb recognised by bios, but after post, it shows 3gb
> available, and upon windows boot, in system it only shows 2gb available;
>
> ive tried swapping the sticks around, its all brand new, just built the
> system last night (10-20-06)
>
> any ideas?
>
> "Charlie Russel - MVP" wrote:
>
>> Sorry, but I don't buy Dells, so can't help there. You could try
>> contacting
>> Dell directly? It might get a response.
>>
>> --
>> Charlie.
>> http://msmvps.com/xperts64
>>
>>
>> "Firdous Gangat" <firdousg@hotmail.com> wrote in message
>> news:OIglWiV8GHA.4996@TK2MSFTNGP03.phx.gbl...
>> > Thanks Guys for your response,
>> >
>> > Dell Dimension 9150 - I had a look through the BIOS after updating it
>> > to
>> > the latest version A06 and I cannot find this setting.
>> >
>> > Any one know if this is supported on this system?
>> >
>> > Regards,
>> >
>> > Firdous
>> >
>> > "JM Tella Llop [MVP Windows]" <jmtella@XXXmvps.org> wrote in message
>> > news:5A082DE0-C9DF-4339-8D5E-844DC4C495F6@microsoft.com...
>> >> Bios: Memory Remaping: Enabled or Disabled?
>> >>
>> >> --
>> >> Jose Manuel Tella Llop
>> >> MVP - Windows
>> >> jmtella@XXXcompuserve.com (quitar XXX)
>> >> http://www.multingles.net/jmt.htm
>> >> news://jmtella.com
>> >>
>> >> Este mensaje se proporciona "como est" sin garantas de ninguna clase,y
>> >> no otorga ningn derecho.
>> >>
>> >> This posting is provided "AS IS" with no warranties, and confers no
>> >> rights.
>> >> You assume all risk for your use.
>> >>
>> >>
>> >>
>> >> "FG" <FG@discussions.microsoft.com> wrote in message
>> >> news:49B7336A-A36B-4DF2-9785-0C4C3D05A3DC@microsoft.com...
>> >>> On Windows Server 2003 x64bit OS with 3GB memory - 2x 1GB and 2 x
>> >>> 512MB.
>> >>>
>> >>> I replaced the 2 x 512MB with 2 x 1GB, therefore the system now has 4
>> >>> x
>> >>> 1GB
>> >>> = total 4GB. The bios see it as 4GB but Windows x64bit see it as 3.5
>> >>> GB.
>> >>> When I put them in pairs, both pairs in Windows report 2GB but when I
>> >>> place
>> >>> all 4 it reports 3.5. Hope that explanation makes sense.
>> >>>
>> >>> Do I need to place the /3GB /PAE switch in the boot.ini?
>> >>> I thought the x64bit sorted out the memory allocation issue?
>> >>> Have you seen this before?
>> >>> Do you think it's a memory, PC H/W or a Server x64bit issue?
>> >>>
>> >>> Thanks in advance.
>> >>>
>> >>> Regards,
>> >>>
>> >>> Firdous
>> >>>
>> >>
>> >
>> >
>>

Steve
Sat Oct 21 13:39:41 CDT 2006

Kahasm wrote:

>ive got a similar problem here vs 4gb memory; mobo is asus a8n32sli delux;
>OS
>is winXP 64 bit version; ram is corsair XMS 3200 (2x2gb pairs) all are same
>model and size
>
>upon boot up, i see 4gb recognised by bios, but after post, it shows 3gb
>available, and upon windows boot, in system it only shows 2gb available;
>
>ive tried swapping the sticks around, its all brand new, just built the
>system last night (10-20-06)
>
>any ideas?
>

According to the manual for your motherboard, you can see the memory
allocation from in the BIOS setup. It suggests that Main > System
Information will show how much RAM there is, and how much is
"appropriated" for hardware support.

It looks like the setting that controls this is Advanced > CPU
Configuration > Memory Setting > Memory Configuration > Hardware Memory
Hole.

--
Steve Foster [SBS MVP]
---------------------------------------
MVPs do not work for Microsoft. Please reply only to the newsgroups.

Steve
Sat Oct 21 13:20:08 CDT 2006

Firdous Gangat wrote:

>Thanks Guys for your response,
>
>Dell Dimension 9150 - I had a look through the BIOS after updating it to
>the latest version A06 and I cannot find this setting.
>
>Any one know if this is supported on this system?

If you take a look around Dell's support forums, you'll soon find that
this is a common issue across Dell's entire range.

They just don't seem to be interested in allowing folks to have full use
of the RAM they're buying.

--
Steve Foster [SBS MVP]
---------------------------------------
MVPs do not work for Microsoft. Please reply only to the newsgroups.

Charlie
Sat Oct 21 15:21:53 CDT 2006

Gee, problems with Dell BIOS and Dell being unresponsive? I'm shocked,
Steve, shocked, do you hear?

--
Charlie.
http://msmvps.com/xperts64


"Steve Foster [SBS MVP]" <steve.foster@picamar.co.uk> wrote in message
news:xn0esqq2s2vvywz00o@msnews.microsoft.com...
> Firdous Gangat wrote:
>
>>Thanks Guys for your response,
>>
>>Dell Dimension 9150 - I had a look through the BIOS after updating it to
>>the latest version A06 and I cannot find this setting.
>>
>>Any one know if this is supported on this system?
>
> If you take a look around Dell's support forums, you'll soon find that
> this is a common issue across Dell's entire range.
>
> They just don't seem to be interested in allowing folks to have full use
> of the RAM they're buying.
>
> --
> Steve Foster [SBS MVP]
> ---------------------------------------
> MVPs do not work for Microsoft. Please reply only to the newsgroups.

Steve
Sat Oct 21 20:58:44 CDT 2006

Charlie Russel - MVP wrote:

>Gee, problems with Dell BIOS and Dell being unresponsive? I'm shocked,
>Steve, shocked, do you hear?

Doesn't take much, does it... <g>

--
Steve Foster [SBS MVP]
---------------------------------------
MVPs do not work for Microsoft. Please reply only to the newsgroups.