Home Forums SQL Server 2005 Administering PAE Overhead RE: PAE Overhead

  • May 25, 2014 at 3:45 pm

    #1716407

    mickyT (5/25/2014)

    Hi Lynn

    For a start I am no expert on these things.

    I couldn't find anything overly specific regarding this, however given the amount of times I saw that using the /3GB switch restricts the use of AWE to 16GB as there is only 1GB of kernal memory available for mapping, it would seem the 2GB requirement may be correct.

    Here's some of pages I looked at:

    http://en.wikipedia.org/wiki/Address_Windowing_Extensions

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

    http://blogs.msdn.com/b/psssql/archive/2012/12/11/how-it-works-sql-server-32-bit-pae-awe-on-sql-2005-2008-and-2008-r2-not-using-as-much-ram-as-expected.aspx

    Thank you, and these are some of the pages I have found as well. Unfortunately they really don't answer the question for me. I guess what I am looking for is something that actually says that you need to allocate an additional 2 GB for the OS above and beyond any memory you may have already allocated to the OS. I just need to find documentation that supports or denies the assertion that PAE incurs a 2 GB overhead in memory. Everything I have read so far leaves this assertion in an ambiguous state.

    On our x86 systems with 32 GB of RAM I have recommended that 4 GB be allocated to the OS from the start. Now, if that 4 GB can cover the PAE overhead and provide the OS with 2 GB of memory as well, good.