Physical Memory Limits: Windows 7
Physical Memory Limits: Windows Server 2008 R2
Physical Memory Limits: Windows Server 2008
Physical Memory Limits: Windows Vista
| Version | Limit on X86 | Limit on X64 |
|---|---|---|
| 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
| Version | Limit on X64 | Limit on IA64 |
|---|---|---|
| Windows Server 2008 R2 Datacenter | 2 GB | |
| Windows Server 2008 R2 Enterprise | 2 GB | |
| 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
| 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 R2 | 4 GB | 32 GB |
Physical Memory Limits: Windows Vista
| Version | Limit on X86 | Limit on X64 |
|---|---|---|
| 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 |
Physical Memory Limits: Windows Server 2003 R2
| Version | Limit on X86 | Limit on X64 |
|---|---|---|
| Windows Server 2003 R2 Datacenter Edition | 64 GB | 1 TB |
| Windows Server 2003 R2 Enterprise Edition | 64 GB | 1 TB |
| Windows Server 2003 R2 Standard Edition | 4 GB | 32 GB |
Physical Memory Limits: Windows Server 2003 SP1
| Version | Limit on X86 | Limit on X64 |
|---|---|---|
| Windows Server 2003 (SP1), Datacenter Edition | 64 GB | 1 TB |
| Windows Server 2003 (SP1), Enterprise Edition | 64 GB | 1 TB |
| Windows Server 2003 (SP1), Standard Edition | 4 GB | 32 GB |
Physical Memory Limits: Windows Server 2003 SP2
| Version | Limit on X86 | Limit on X64 |
|---|---|---|
| Windows Server 2003 (SP2), Datacenter Edition | 64 GB | 1 TB |
| Windows Server 2003 (SP2), Enterprise Edition | 64 GB | 1 TB |
| Windows Server 2003 (SP2), Standard Edition | 4 GB | 32 GB |
Physical Memory Limits: Windows Server 2003
| Version | Limit on X86 | Limit on X64 |
|---|---|---|
| Windows Server 2003, Datacenter Edition | 64 GB | 512 GB |
| Windows Server 2003, Enterprise Edition | 64 GB | 512 GB |
| Windows Server 2003, Standard Edition | 4 GB | |
| Windows Server 2003, Web Edition | 2 GB | |
| Windows Small Business Server 2003 | 4 GB | |
| Windows Compute Cluster Server 2003 | 32 GB | |
| Windows Storage Server 2003, Enterprise Edition | 8 GB | |
| Windows Storage Server 2003 | 4 GB |
(From Microsoft)