Only 3GB showing?.....

[Eric Miller]

OS XP Pro SP2
MB P35 Neo2

I just installed an additional 4GB totalling 6GB and System Properties and
the Task Manager reports 3.25GB, but in System Information does show the
total RAM.

My total RAM is available correct? Even though the other two info only
reports half?

 

[Ken]

OS XP Pro SP2
MB P35 Neo2

I just installed an additional 4GB totalling 6GB and System Properties and
the Task Manager reports 3.25GB, but in System Information does show the
total RAM.

My total RAM is available correct? Even though the other two info only
reports half?

It is my understanding that the 32bit version of WinXP only addresses
3.2 GB of RAM, no matter how much is installed. However, someone who is
more expert can confirm that. Try this:
http://members.cox.net/slatteryt/RAM.html

Ken K

 

[Shenan Stanley]

OS XP Pro SP2
MB P35 Neo2

I just installed an additional 4GB totalling 6GB and System
Properties and the Task Manager reports 3.25GB, but in System
Information does show the total RAM.

My total RAM is available correct? Even though the other two info
only reports half?

Windows XP Professional 32bit or 64bit?
32bit only supports 4GB maximum - and then, because of assorted reasons, you
will not usually see more than 3-3.5GB to utilize.
64bit does not share the same limitations.

What makes you think you need that much memory?

 

[Eric Miller]

Running VS2005 with Win2008 VM. Looks like I am going to have to reverse
this setup, because this is my test machine and I need the extra memory to
create a non-production doman in VS with Win2008.

 

[Tim Slattery]

OS XP Pro SP2
MB P35 Neo2

I just installed an additional 4GB totalling 6GB and System Properties and
the Task Manager reports 3.25GB, but in System Information does show the
total RAM.

My total RAM is available correct? Even though the other two info only
reports half?

Probably not. It looks to me like you have a 64-bit capable
motherboard but you're running 32-bit XP. That restricts you to a 4GB
(2**32) address space, which must be used to access video RAM, BIOS,
and other things besides system RAM. See
http://members.cox.net/slatteryt/RAM.html

That said, the fact that System Properties and Task Man show you the
entire 6GB makes me wonder about that diagnosis.

 

[Ken Blake, MVP]

OS XP Pro SP2
MB P35 Neo2

I just installed an additional 4GB totalling 6GB and System Properties and
the Task Manager reports 3.25GB, but in System Information does show the
total RAM.

My total RAM is available correct? Even though the other two info only
reports half?

All 32-bit versions of Windows (not just XP) have a 4GB address space.
That's the theoretical upper limit beyond which you can not go.

But you can't use the entire 4GB of address space. Even though you
have a 4GB address space, you can only use *around* 3.1GB of RAM.
That's because some of that space is used by hardware and is not
available to the operating system and applications. The amount you can
use varies, depending on what hardware you have installed, but ranges
from about 3 - 3.5GB--
usually around 3.1GB.

Note that the hardware is using the address *space*, not the actual
RAM itself. The rest of the RAM goes unused because there is no
address space to map it too.

 

[Colin Barnhorst]

There is no fixed number and it is not Windows that reduces the memory
available, but the BIOS. All manufacturer's set up the BIOS to enable
memory-mapped IO for hardware devices and this memory is not shown to the
user directly. It is the price we pay for high-performance devices like our
video cards. The range is from 2.2GB to 3.5GB across my systems.

 

[Eric Miller]

Even the 32bit Win2008 Server?

All 32-bit versions of Windows (not just XP) have a 4GB address space.
That's the theoretical upper limit beyond which you can not go.

But you can't use the entire 4GB of address space. Even though you
have a 4GB address space, you can only use *around* 3.1GB of RAM.
That's because some of that space is used by hardware and is not
available to the operating system and applications. The amount you can
use varies, depending on what hardware you have installed, but ranges
from about 3 - 3.5GB--
usually around 3.1GB.

Note that the hardware is using the address *space*, not the actual
RAM itself. The rest of the RAM goes unused because there is no
address space to map it too.

 

[Colin Barnhorst]

No. See the table in the link and find the edition of Windows in question.

http://msdn.microsoft.com/en-us/library/aa366778.aspx#physical_memory_limits_windows_server_2003

Even the 32bit Win2008 Server?

 

[Colin Barnhorst]

Additional note: When you scroll down to the Windows Server 2003 table you
sill see that WS2k3 32bit Standard Edition is limited to 4GB but Enterprise
and DataCenter are not and that SP1 also makes a difference for some
editions.

Even the 32bit Win2008 Server?