Confusion in AWE

suppose i have enabled only AWE option in sql server but i didn't add 3

GB switch in boot.ini. in this case what will be the effect on physical memory?

Having /PAE in your boot.ini file allows a 32-bit OS to access more than 4GB ofRAM using AWE. Using /3GB in the boot.ini file only reserves 1GB for the OS, and allows applications to use 3GB of RAM instead of the normal 2GB of RAM.

http://support.microsoft.com/kb/274750

http://msdn2.microsoft.com/en-us/library/ms175581.aspx

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/PAE can you be used only for intel

In case other model what can be used to access more than 4GB of memory

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Hi Satyanarayana,

what platform is your sql machine. Also is it 32bit or 64 bit? And how much RAM is on the box.

Jag

|||we are using AMD opteron processor. it is 32 bit and about 4GB RAM|||

With only 4gb of RAM there is no need for /PAE. Using /3GB will allow for use of up to 3GB of Virtual address space by SQL Server. This will likely be sufficient for a machine with 4GB of RAM.

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AWE will be in effect with or without the /3GB switch. The AWE mechanism require the process using it to "map" the memory into a window in virtual memory. The size of this window will be greater (and therefore more RAM could be mapped simulataneously if the /3GB switch is used)

Thanks, Ron D.

|||today it is 4GB. tomorrow definitely physical memory will be increased (say 8 GB). in that case what can done for non intel machines to use more than 3GB of memory|||how do we know the AWE is in effect?|||

The following message should be in the errorlog:

"Address Windowing Extensions is enabled. This is an informational message only; no user action is required."

Thanks, Ron D.