Physical address expansion (PAE) and application memory Adjustment

Physical address extensions (PAE) and Applications Program Memory adjustment update date: 01/21/2005

Physical address expansion (PAE) x86 and application memory Adjustment

Physical address expansion (PAE) x86 and application memory adjustment called 4 GB adjustment (4gt) are complementary technologies for computers using Intel processors.

The application memory adjustment provides less virtual memory for the operating system to provide more virtual memory for the application. PAE x86 allows the use of address window extension (AWE) API series software to run on computers with Intel Pentium Pro or faster processors and Windows Server 2003 Enterprise Edition or Windows Server 2003 datacenter edition, to map more physical memory to the virtual address space of the application.

For example, if your computer runs Pentium Pro or a faster processor and has 16 GB of physical memory (the maximum memory supported by application memory adjustment ), you can use the application memory adjustment to allocate 3 GB virtual memory (1 GB for the operating system) to the application ). The given application can then lock the physical memory. With the awe API series and the PAE x86 kernel, the remaining 12 GB physical memory can be used by applications for caching purposes. Therefore, applications can access up to 15 GB of physical memory.

For more information, see:

•	Application memory Adjustment
•	Physical address extension (PAE) Overview

Key Points

•	When the application memory is adjusted on a computer with more than 16 GB physical memory, the physical memory with more than 16 GB address will be ignored by the operating system. For more information, see enable application memory adjustment.