How to configure SQL Server to use more than 2 GB of physical memory:

AWE is not needed and cannot be configured on 64-bit operating systems.

Address Windowing Extensions (AWE) allowing use of physical memory over 4 gigabytes (GB)

Standard 32-bit addresses can map a maximum of 4 GB of memory. The standard address spaces of 32-bit processes are therefore limited to 4 GB. By default, on 32-bit Microsoft Windows operating systems, 2 GB are reserved for the operating system, and 2 GB are made available to the application. If you specify a /3gb parameter in the Boot.ini file of Windows 2000 Advanced Server, the operating system reserves only 1 GB of the address space, and the application can access up to 3 GB.

To support more than 4 GB of physical memory on 32-bit operating systems, you must add the /pae parameter to the Boot.ini file and reboot the computer. In Windows Server 2003, PAE is automatically enabled only if the server is using hot-add memory devices. In this case, you do not have to use the /pae parameter on a system that is configured to use hot-add memory devices.

To configure Windows 2000 (Advanced or Datacenter), you must enter one of the following switches in the boot line of the boot.ini file, and reboot the server:

·         3 to 4GB RAM:               /3GB (AWE support is not used)

·         4 to 16 GB RAM:            /3GB /PAE and AWE

• 16GB + RAM:                 /PAE (/3GB must not be used) and AWE

The following example shows how to enable AWE and configure a limit of 6 GB for the max server memory option:

sp_configure 'show advanced options', 1

RECONFIGURE

GO

sp_configure 'awe enabled', 1

RECONFIGURE

GO

sp_configure 'max server memory', 6144

RECONFIGURE

GO