SQL Server Min & Max Memory Settings

  • Hello Everyone,

    We upgraded our SQL production servers memory from 8GB to 16GB last week and that server is Win2003 Server installed. I look at the SQL server properties this morning and I saw something a bit strange... Dynamic Memory section Min Memory is set from 10 MB to Max Mem is 4GB even we have 16GB on the Server. Is that better to change it up to 16GB for Max Memory?

    Also performance wise...I don't get best performance over upgrading memory, anything else I need to look at?

    I use RAID 0 for all my DB .MDF and .LDF.

    Thanks.

  • Leo (5/26/2009)


    Is that better to change it up to 16GB for Max Memory?

    Absolutely not. If you do that, SQL will try and take all 16 GB and it may starve the OS of memory. You'll get some very interesting error messages and possibly even a server crash.

    With 16GB memory, set SQL's max memory to around 12GB-13GB. No more than 14. The OS needs memory to manage memory and the more memory in the server, the more the OS needs.

    Gail Shaw
    Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
    SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability

    We walk in the dark places no others will enter
    We stand on the bridge and no one may pass
  • Also performance wise...I don't get best performance over upgrading memory, anything else I need to look at?

    Increasing RAM alone does not boost performance for your systems, There are various factors that contribute towards the system performance 🙂

  • If this is a 32bit version of Windows have you also enabled PAE and AWE?



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  • When looking at the dynamic setting - does it show that you can set it to 16GB? What is the SQL Server version you are running - Standard or Enterprise? If Standard, you are not going to be able to able to modify it since that version can only ever use 2GB of memory anyways.

    Jeffrey Williams
    “We are all faced with a series of great opportunities brilliantly disguised as impossible situations.”

    ― Charles R. Swindoll

    How to post questions to get better answers faster
    Managing Transaction Logs

  • Hi Jeffrey,

    Yes, it said 16GB and Enterprise Version (SQL 2000).

    Thanks.

  • Okay, then I would go with Gail's recommendation of 12GB max memory. You don't want to go higher than that, well maybe 13GB would be okay - but, you'll have to watch it to make sure.

    Jeffrey Williams
    “We are all faced with a series of great opportunities brilliantly disguised as impossible situations.”

    ― Charles R. Swindoll

    How to post questions to get better answers faster
    Managing Transaction Logs

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