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  1. #1
    Join Date
    Jul 2002
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    Lima - Perú
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    Question Unanswered: HyperThreading with SQL Server 2000

    Hi:

    I have a server with 4 processors with hyperthreading, so my Windows Server 2003 Enterprise Edition see 8 processors. I have installed SQL Server 2000 Enterprise Edition and see 8 processors. The question is : if i install SQL Server 2000 Standard Edition, how many processors see and use 4 or 8 ?

    I know that i have to license only 4 processors according to the Microsoft License, but,really, how many processors see and use???.

  2. #2
    Join Date
    May 2002
    Posts
    299
    sqlserver will see all logical processsors (i.e. 8) but you should limit the paralellism to only to 4 (physical) to avoid possible internal para blocking (i.e. max degree of paralellism).

    Leaving HT on is a good thing but it's useless to allow all 8 schedulers to work on a single query.
    --
    -oj
    http://www.rac4sql.net

  3. #3
    Join Date
    Nov 2002
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    Jersey
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    10,322
    Why did you enable hyper-threading?

    Even M$ admits that you probably are better off w/out it
    Brett
    8-)

    It's a Great Day for America everybody!

    dbforums Yak CorralRadio 'Rita
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    I'm Good Once as I ever was

    The physical order of data in a database has no meaning.

  4. #4
    Join Date
    Jul 2002
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    Question What???

    Because my server have this property by default then the operating system use this, i did think that use that was better for perfomance...i'm confuse.

  5. #5
    Join Date
    Nov 2002
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    Rob is an MVP and does a lot of sql server work

    http://www.sqlteam.com/forums/topic.asp?TOPIC_ID=55887


    Also, it's a lot of excess for a 10-20% (10 more likely) Perf gain...Plus you have a quad...I don't even think they list a quad

    http://support.microsoft.com/default.aspx/kb/322385
    Brett
    8-)

    It's a Great Day for America everybody!

    dbforums Yak CorralRadio 'Rita
    dbForums Member List
    I'm Good Once as I ever was

    The physical order of data in a database has no meaning.

  6. #6
    Join Date
    May 2002
    Posts
    299
    Please take a look at Kevin's article , Bare Metal Tuning (will require sqlmag sub to access the article).
    http://www.windowsitpro.com/SQLServe...ver_46492.html

    In general, HT does give a boost in SQL perf (20-30% gain according to the TPC-C he and a Performance Engr from HP did). If you have an app that pushes L1/L2 cache heavily, turning off HT would only then be a good idea.
    --
    -oj
    http://www.rac4sql.net

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