[Modify] how to modify the/PAE/AWE/3 gb parameters of the bootini File

Source: Internet
Author: User

How to modify the PAE | awe | 3 GB parameter of the bootini file: we all know that parameters can be added after boot. ini, such as: PAE: enable the system to access 3 GB of physical memory exceeding 4 GB: Enable the applicationProgramWith over 2 GB of memory, up to 3 GB awe: enables applications to use over 3 GB of memory. I don't know what I understand above, right,

My problem is:
1. What are the specific work of these parameters?
2. If I have 4 GB memory, can I use the PAE and 3 GB switches at the same time? Can PAE and awe be used simultaneously?
3. Since awe enables applications to use more than 3 GB of memory, it is useless if it is 3 GB. Simply use awe.
4. Under what circumstances does awe generally be used? Is it available for 3 GB with awe?

Answer:
The Standard 32-bit address can map up to 4 GB memory. Therefore, the standard address space for 32-bit processes is limited to 4 GB. By default, the 32-bit Microsoft Windows operating system reserves 2 GB space for the operating system, and the other 2 GB space can be used by applications. If the/3 GB parameter is specified in the boot. ini file of Windows server, the operating system retains only 1 GB of address space, and applications can access up to 3 GB of space.

Awe is a set of extensions of Windows Memory Management functions. It enables applications to use more memory than 2-3 GB memory that can be used through standard 32-bit addressing. Awe allows applications to obtain physical memory and dynamically map non-Paging memory views to 32-bit address space. Although the 32-bit address space is limited to 4 GB, the non-Paging memory can be much larger than 4 GB. This allows applications that require a large amount of memory (such as large database systems) to use much larger memory than the 32-bit address space.

If the computer has more than 16 GB of available physical memory, the operating system requires 2 GB of process address space for the system to use. Therefore, only 2 GB of user mode address space is supported. To enable awe to use more than 16 GB memory, ensure that the/3 GB parameter is not in the boot. ini file. Otherwise, the operating system cannot address memory larger than 16 GB.

Awe allows a 32-bit architecture to allocate more than 4 GB of physical memory. Awe should be used only when the available physical memory is larger than the virtual address space in user mode.
To enable the 32-bit operating system to support more than 4 GB physical memory, you must add the/PAE parameter to the boot. ini file and restart the computer.

In Windows Server 2003, if the server uses a hot-added memory device, the PAE is automatically enabled. In this case, you do not need to use the/PAE parameter in the system configured to use hot-added memory devices. In any other case, the/PAE parameter must be used in the boot. ini file to take advantage of the memory exceeding 4 GB.
---- Suy

Based on my experience, if the/PAE switch is not used, the operating system cannot use physical memory larger than 4 GB. Generally, for each process, the virtual address space allocated to the user-mode process is 2 GB, and the virtual address space allocated to the operating system is 2 GB. If the server has 4 GB physical memory, you can use the 3 GB switch to enable applications such as SQL to use memory larger than 2 GB.
You can enable both PAE and 3 GB.

For more information about PAE and awe, see the following link:
Windows Server 2003 and Windows 2000 support large memory
Http://support.microsoft.com/kb/283037/
In my experience, if the system uses boot. if the/3 GB item in the INI file is restarted and the system's physical memory exceeds 16 GB, the operating system does not use additional physical random access memory (RAM ). That is to say, if your physical memory is larger than 16 GB, we do not recommend that you use the 3G switch. In this case, the operating system will not use any memory larger than 16 GB. This behavior is caused by kernel virtual memory space.
If your physical memory is greater than 3 GB but less than 16 GB, you can use the/3 GB switch.

Awe is an application programming interface (API) for the memory manager function. It enables the program to address more memory-4 GB memory space exceeding the standard 32-bit addressing. Awe enables the program to retain the physical memory as non-Paging memory, and then dynamically map the non-Paging memory part to the program's memory working set. This process enables memory-intensive programs (such as large database systems) to retain a large amount of physical memory for data, without having to swap paging files for use. On the contrary, data is exchanged in the work set and the reserved memory exceeds 4 GB. In addition, the memory manager is open for memory exceeding the 4 GB memory range, and awe plays a role through Pae. Without PAE, awe cannot retain memory larger than 4 GB.

Example
The following example shows how to enable awe and configure Max server memory to a limit of 6 GB:

Sp_configure 'show advanced options', 1
Reconfigure
Go
Sp_configure 'awe enabled', 1
Reconfigure
Go
Sp_configure 'max Server Memory ', 6144
Reconfigure
Go

 

From: http://butian.org/knowledge/windows/1376.html

Use/PAE and awe

Http://topic.csdn.net/u/20100415/11/916f7b3e-c9b8-449a-8b41-6f74d583f1b6.html

 

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