Are there maximum RAM limitations for the operating system?

Operating system maximum RAM limits

Here is a breakdown of Windows operating systems.

Windows 8 limits on physical memory:

• 32-bit Edition
  • Windows 8 = 4GB
  • Windows 8 Professional = 4GB
  • Windows 8 Enterprise = 4GB
• 64-bit Edition
  • Windows 8  = 128GB
  • Windows 8 Professional = 512GB
  • Windows 8 Enterprise = 512GB

Windows 7 limits on physical memory:

• 32-bit Edition
  • Windows 7 Ultimate = 4GB
  • Windows 7 Enterprise = 4GB
  • Windows 7 Professional = 4GB
  • Windows 7 Home Premium = 4GB
  • Windows 7 Home Basic = 4GB
  • Windows 7 Starter = 2GB
• 64-bit Edition
  • Windows 7 Ultimate = 192GB
  • Windows 7 Enterprise = 192GB
  • Windows 7 Professional = 192GB
  • Windows 7 Home Premium = 16GB
  • Windows 7 Home Basic = 8GB
  • Windows 7 Starter = N/A

 

Windows Vista limits on physical memory:

• 32-bit Edition
  • Windows Vista Ultimate = 4GB
  • Windows Vista Enterprise = 4GB
  • Windows Vista Business = 4GB
  • Windows Vista Home Premium = 4GB
  • Windows Vista Home Basic = 4GB
  • Windows Vista Starter = 1GB
• 64-bit Edition
  • Windows Vista Ultimate = 128GB
  • Windows Vista Enterprise = 128GB
  • Windows Vista Business = 128GB
  • Windows Vista Home Premium = 16GB
  • Windows Vista Home Basic = 8GB
  • Windows Vista Starter = N/A

Windows Home Server = 4GB

Windows XP limits on physical memory:

• 32-bit Edition
  • Windows XP = 4GB
  • Windows XP Starter = 512MB
• 64-bit Edition
  • Windows XP = 128GB
  • Windows XP Starter = N/A

Source = Memory Limits for Windows Releases