4 Gb Ram: Windows reads only 3 GB?

[René Davis Ramirez]

I have a dual Xeon with 4 gb of Ram ,4 modules of 1 gb each of the same type,
they all work if installed 2 by 2 in any combination. The mainborad with 4
modules of 512 mb sees everything; I've tested just to check if there was
something wrong on it. If I install the 4 1 gb moduls I can't see more than 3
gb. Where's the trick?

[René Davis Ramirez]

Hardware is ok I see all the memory during the boot of the machine, and if a
try a linux live cd, (knoppix) it's all there

"Leythos" ha scritto:

> In article >,
> says...
> > I have a dual Xeon with 4 gb of Ram ,4 modules of 1 gb each of the same type,
> > they all work if installed 2 by 2 in any combination. The mainborad with 4
> > modules of 512 mb sees everything; I've tested just to check if there was
> > something wrong on it. If I install the 4 1 gb moduls I can't see more than 3
> > gb. Where's the trick?
>
> What does the motherboard vendor say?
>
> Some motherboards, while they permit installation of 4 sticks of Memory,
> they don't fully support it.
>
> What motherboard? Have you checked to see if there is a BIOS update?
>
> --
>
>
> remove 999 in order to email me
>

[SergeV]

I thought this is a Microsoft forum. :-((
Are you banned @ google?

"Rene Davis Ramirez" > wrote
in message
> Hardware is ok I see all the memory during the boot of the machine,
> and if a
> try a linux live cd, (knoppix) it's all there

[Kerry Brown]

You need an OS that supports more than 4 GB. Windows XP 32 bit only supports
4 GB. Some of the address space is needed for the system. Depending on your
motherboard it will be hard to get Windows to show more than somewhere
around 3.25 GB. If you want to run Windows with more ram than that you'll
need to use a 64 bit version like XP 64 bit or Vista 64 bit. Make sure that
drivers are available for your hardware before you switch to a 64 bit
version of Windows. 32 bit drivers won't work in a 64 bit OS.

--
Kerry
MS-MVP Windows - Shell/User
http://www.vistahelp.ca


René Davis Ramirez wrote:
> I have a dual Xeon with 4 gb of Ram ,4 modules of 1 gb each of the
> same type, they all work if installed 2 by 2 in any combination. The
> mainborad with 4 modules of 512 mb sees everything; I've tested just
> to check if there was something wrong on it. If I install the 4 1 gb
> moduls I can't see more than 3 gb. Where's the trick?

[Jerry]

Do a Google search on boot.ini and you'll find info about switches needed
when memory is above 3Gb.

"René Davis Ramirez" > wrote in
message ...
>I have a dual Xeon with 4 gb of Ram ,4 modules of 1 gb each of the same
>type,
> they all work if installed 2 by 2 in any combination. The mainborad with 4
> modules of 512 mb sees everything; I've tested just to check if there was
> something wrong on it. If I install the 4 1 gb moduls I can't see more
> than 3
> gb. Where's the trick?

[Loren Pechtel]

On Fri, 15 Sep 2006 05:22:01 -0700, René Davis Ramirez
> wrote:

>I have a dual Xeon with 4 gb of Ram ,4 modules of 1 gb each of the same type,
>they all work if installed 2 by 2 in any combination. The mainborad with 4
>modules of 512 mb sees everything; I've tested just to check if there was
>something wrong on it. If I install the 4 1 gb moduls I can't see more than 3
>gb. Where's the trick?

32-bit OSes can't see the full 4gb because some of the space is used
for other purposes.

[Mike]

In article >,
says...
>
>Do a Google search on boot.ini and you'll find info about switches needed
>when memory is above 3Gb.
>
>"René Davis Ramirez" > wrote in
>message ...
>>I have a dual Xeon with 4 gb of Ram ,4 modules of 1 gb each of the same
>>type,
>> they all work if installed 2 by 2 in any combination. The mainborad with 4
>> modules of 512 mb sees everything; I've tested just to check if there was
>> something wrong on it. If I install the 4 1 gb moduls I can't see more
>> than 3
>> gb. Where's the trick?
>
>

Those switches won't help. They address the virtual memory. This is a physical memory
issue. As has been stated, the hardware takes some of the memory space (PCI devices, the
newest PCI is quite the memory gobbler and probably the main culprit). The only way to get
the memory back, as stated, is to run 64 bit XP (and that may not get it all back).

[Bob Willard]

Mike wrote:

> In article >,
> says...
>
>>Do a Google search on boot.ini and you'll find info about switches needed
>>when memory is above 3Gb.
>>
>>"René Davis Ramirez" > wrote in
>>message ...
>>
>>>I have a dual Xeon with 4 gb of Ram ,4 modules of 1 gb each of the same
>>>type,
>>>they all work if installed 2 by 2 in any combination. The mainborad with 4
>>>modules of 512 mb sees everything; I've tested just to check if there was
>>>something wrong on it. If I install the 4 1 gb moduls I can't see more
>>>than 3
>>>gb. Where's the trick?
>>
>>
>
> Those switches won't help. They address the virtual memory. This is a physical memory
> issue. As has been stated, the hardware takes some of the memory space (PCI devices, the
> newest PCI is quite the memory gobbler and probably the main culprit). The only way to get
> the memory back, as stated, is to run 64 bit XP (and that may not get it all back).
>

The switch (/3GB or something like that) does help some. IIRC, using that
switch makes ~3.2GB usable; better than 3, but still not the whole 4 yards.
--
Cheers, Bob

[Kerry Brown]

Bob Willard wrote:
> Mike wrote:
>
>> In article >,
>> says...
>>
>>> Do a Google search on boot.ini and you'll find info about switches
>>> needed when memory is above 3Gb.
>>>
>>> "René Davis Ramirez" >
>>> wrote in message
>>> ...
>>>> I have a dual Xeon with 4 gb of Ram ,4 modules of 1 gb each of the
>>>> same type,
>>>> they all work if installed 2 by 2 in any combination. The
>>>> mainborad with 4 modules of 512 mb sees everything; I've tested
>>>> just to check if there was something wrong on it. If I install the
>>>> 4 1 gb moduls I can't see more than 3
>>>> gb. Where's the trick?
>>>
>>>
>>
>> Those switches won't help. They address the virtual memory. This is
>> a physical memory issue. As has been stated, the hardware takes some
>> of the memory space (PCI devices, the newest PCI is quite the memory
>> gobbler and probably the main culprit). The only way to get the
>> memory back, as stated, is to run 64 bit XP (and that may not get it
>> all back).
>
> The switch (/3GB or something like that) does help some. IIRC, using
> that switch makes ~3.2GB usable; better than 3, but still not the
> whole 4 yards.

It gives applications 3 GB to work with but it does this by taking 1 GB from
the system. Only applications written to work with this will benefit at the
expense of slowing down some system functions. The only real benefit to the
/3 GB switch for most people is cosmetic, System Properties shows a bit more
RAM.

--
Kerry
MS-MVP Windows - Shell/User
http://www.vistahelp.ca

[Loren Pechtel]

On Sat, 16 Sep 2006 09:47:46 -0400, Bob Willard
> wrote:

>The switch (/3GB or something like that) does help some. IIRC, using that
>switch makes ~3.2GB usable; better than 3, but still not the whole 4 yards.

It makes 3GB useable by one program, otherwise the limit is 2GB.

I've got 4GB physical, 3.25GB available, no /3gb switch.