Configuring HP SIM for Optimal Performance in Large Environments

Advanced Windowing Extensions (AWE) is a method that the Windows operating system can make
more
than 4 GB available to applications through system calls. To take advantage of AWE memory,
you
must configure both Microsoft Windows 2008 x32 and Microsoft SQL Server.
PAE
PAE is the added ability of the IA32 processor to address more than 4 GB of physical memory. Note
that this section does not apply to 64-bit versions of Windows.
Note:
This applies specifically to Windows Server 2008 Enterprise Edition.
Windows Server 2008 x32 Standard Edition cannot address above 4GB
of RAM.
The following table lists the maximum physical memory that a Windows version can recognize, with the
PAE switch enabled (note that Windows Server 2008 R2 does not offer a 32-bit version):
Table 3: Maximum supported memory for Server 2008 R2 versions
Version Limit on X64
Windows Server 2008 R2 Datacenter 2 TB
Windows Server 2008 R2 Enterprise 2 TB
Windows Server 2008 R2 Foundation 8 GB
Windows Server 2008 R2 Standard 32 GB
Windows HPC Server 2008 R2 128 GB
Windows Web Server 2008 R2 32 GB
Table 4 : Maximum supported memory for Server 2008 versions
Version Limit on X86 Limit on X64
Windows Server 2008 Datacenter 64 GB 1 TB
Windows Server 2008 Enterprise 64 GB 1 TB
Windows Server 2008 HPC Edition 128 GB
Windows Server 2008 Standard 4 GB 32 GB
Windows Small Business Server 2008 4 GB 32 GB
Windows Web Server 2008 4 GB 32 GB
Typically, a process running under Windows Server 2008 x32 can access up to 2 GB of memory
address space with some of the memory being physical memory and some being virtual memory. The
more programs (and, therefore, more processes) that run, the more memory you commit up to the full 2
GB of address space.
When this situation occurs, the paging process increases dramatically and performance might be
negatively impacted. The Windows Server 2008 x32 memory managers use PAE to provide more
physical memory to a program. This reduces the need to swap the memory of the page file and results
in increased performance. The program itself is not aware of the actual memory size. All the memory
management and allocation of the PAE memory is handled by the memory manager independently of
the programs that run.
User-mode address space on 32-bit x86