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Physical Address Extension - PAE Memory and Windows
http://msdn.microsoft.com/en-us/windows/hardware/gg487503
Operating System Support. The PAE kernel is not enabled
by default for systems that can support more than 4 GB
of RAM.
To boot the system and utilize PAE memory, the /PAE
switch must be added to the corresponding entry in the
Boot.ini file. If a problem should arise, Safe Mode may
be used, which causes the system to boot using the
normal kernel (support for only 4 GB of RAM) even if
the /PAE switch is part of the Boot.ini file.
The PAE mode kernel requires an Intel Architecture
processor, Pentium Pro or later, more than 4 GB of RAM,
and Windows 2000, Windows XP, or Windows Server 2003.
That is *only* true for those that doesn't know any better.Ken said:It's not just XP (and it it's not exactly 3.33GB on all computers).
It's *all* 32-bit client versions of Windows; you will have the same
issue with Windows 7 unless you go to a 64-bit version of it.
All 32-bit client versions of Windows (not just XP/Vista/7) have a 4GB
address space (64-bit versions can use much more). That's the
theoretical upper limit beyond which you can not go.
But you can't use the entire 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 can
range from as little as 2GB to as much as 3.5GB. It's usually around
3.1GB.
Note that the hardware is using the address *space*, not the actual
RAM itself. If you have a greater amount of RAM, the rest of the RAM
goes unused because there is no address space to map it to.
Physical Address Extension - PAE Memory and Windows
http://msdn.microsoft.com/en-us/windows/hardware/gg487503
Operating System Support. The PAE kernel is not enabled
by default for systems that can support more than 4 GB
of RAM.
To boot the system and utilize PAE memory, the /PAE
switch must be added to the corresponding entry in the
Boot.ini file. If a problem should arise, Safe Mode may
be used, which causes the system to boot using the
normal kernel (support for only 4 GB of RAM) even if
the /PAE switch is part of the Boot.ini file.
The PAE mode kernel requires an Intel Architecture
processor, Pentium Pro or later, more than 4 GB of RAM,
and Windows 2000, Windows XP, or Windows Server 2003.