Address Windowing Extensions
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Address Windowing Extensions (AWE) is a Microsoft Windows Application Programming Interface that allows a 32-bit software application to access physical memory greater than 4GB. The process of mapping an application's virtual address space to physical memory is known as 'windowing'. The virtual address space or 'memory window' of a 32-bit application is limited to 4GB (2^32-1 bytes), but by exposing that memory window to different parts of the physical memory, the application can have access to physical memory greater than 4GB.
The AWE is beneficial to certain data-intensive applications, such as database management systems (for example Microsoft SQL Server) and scientific and engineering software, that need access to very large caches of data.
AWE usage is encoded into the application itself. An application must have the Lock Pages in Memory privilege to use AWE. For an application to have access to memory in excess of 4GB, the Microsoft Windows Operating System executing the application must have Physical Address Extension support. All versions of Microsoft Windows that support Physical Address Extension place limits on the amount of physical memory that it makes available.
