Memory limits of various Windows versions

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Thinking of a memory upgrade? An operating system upgrade? Here’s a table from msdn stating the limits imposed by 32 and 64 bit editions of various Windows versions.

Physical Memory Limits: Windows 7

The following table specifies the limits on physical memory for Windows 7.

Version Limit in 32-bit Windows Limit in 64-bit Windows
Windows 7 Ultimate 4 GB 192 GB
Windows 7 Enterprise 4 GB 192 GB
Windows 7 Professional 4 GB 192 GB
Windows 7 Home Premium 4 GB 16 GB
Windows 7 Home Basic 4 GB 8 GB
Windows 7 Starter 2 GB 2 GB

Physical Memory Limits: Windows Server 2008 R2

The following table specifies the limits on physical memory for Windows Server 2008 R2. Windows Server 2008 R2 is available only in 64-bit editions.

Version Limit in 64-bit Windows
Windows Server 2008 R2 Datacenter 2 TB
Windows Server 2008 R2 Enterprise 2 TB
Windows Server 2008 R2 for Itanium-Based Systems 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

Physical Memory Limits: Windows Server 2008

The following table specifies the limits on physical memory for Windows Server 2008. Limits greater than 4 GB for 32-bit Windows assume that PAE is enabled.

Version Limit in 32-bit Windows Limit in 64-bit Windows
Windows Server 2008 Datacenter 64 GB 2 TB
Windows Server 2008 Enterprise 64 GB 2 TB
Windows Server 2008 HPC Edition Not applicable 128 GB
Windows Server 2008 Standard 4 GB 32 GB
Windows Server 2008 for Itanium-Based Systems Not applicable 2 TB
Windows Small Business Server 2008 4 GB 32 GB
Windows Web Server 2008 4 GB 32 GB

Physical Memory Limits: Windows Vista

The following table specifies the limits on physical memory for Windows Vista.

Version Limit in 32-bit Windows Limit in 64-bit Windows
Windows Vista Ultimate 4 GB 128 GB
Windows Vista Enterprise 4 GB 128 GB
Windows Vista Business 4 GB 128 GB
Windows Vista Home Premium 4 GB 16 GB
Windows Vista Home Basic 4 GB 8 GB
Windows Vista Starter 1 GB Not applicable

Physical Memory Limits: Windows Home Server

Windows Home Server is available only in a 32-bit edition. The physical memory limit is 4 GB.

Physical Memory Limits: Windows Server 2003

The following table specifies the limits on physical memory for Windows Server 2003. Limits over 4 GB for 32-bit Windows assume that PAE is enabled.

Version Limit in 32-bit Windows Limit in 64-bit Windows
Windows Server 2003 with Service Pack 2 (SP2), Datacenter Edition 128 GB

64 GB with 4GT

2 TB
Windows Server 2003 with Service Pack 2 (SP2), Enterprise Edition 64 GB 2 TB
Windows Storage Server 2003, Enterprise Edition 8 GB Not applicable
Windows Storage Server 2003 4 GB Not applicable
Windows Server 2003 R2 Datacenter Edition

Windows Server 2003 with Service Pack 1 (SP1), Datacenter Edition

128 GB

16 GB with 4GT

1 TB
Windows Server 2003 R2 Enterprise Edition

Windows Server 2003 with Service Pack 1 (SP1), Enterprise Edition

64 GB

16 GB with 4GT

1 TB
Windows Server 2003 R2 Standard Edition

Windows Server 2003, Standard Edition SP1

Windows Server 2003, Standard Edition SP2

4 GB 32 GB
Windows Server 2003, Datacenter Edition 128 GB

16 GB with 4GT

512 GB
Windows Server 2003, Enterprise Edition 32 GB

16 GB with 4GT

64 GB
Windows Server 2003, Standard Edition 4 GB 16 GB
Windows Server 2003, Web Edition 2 GB Not applicable
Windows Small Business Server 2003 4 GB Not applicable
Windows Compute Cluster Server 2003 Not applicable 32 GB

Physical Memory Limits: Windows XP

The following table specifies the limits on physical memory for Windows XP.

Version Limit in 32-bit Windows Limit in 64-bit Windows
Windows XP 4 GB 128 GB
Windows XP Starter Edition 512 MB Not applicable

Physical Memory Limits: Windows 2000

The following table specifies the limits on physical memory for Windows 2000.

Version Limit in 32-bit Windows
Windows 2000 Professional 4 GB
Windows 2000 Server 4 GB
Windows 2000 Advanced Server 8 GB
Windows 2000 Datacenter Server 32 GB
  • Chris Hug

    I have an old machine running windows 2000 and I just upgraded the ram from 1GB to 4GB. Windows 2000 will not boot with 4GB installed (BSOD or just reboots). It works fine when I pull out one stick though. I tried switching sticks while using 3GB to see if a stick was bad and it worked with 3GB every time. Any ideas?

    • BIOS update? As far as I remember it should work. I had 32bit machines even with 8GB of RAM. Windows would simply report 3.something GB available.