Post reply

CPU usage

  • March 19, 2013 at 5:48 am

    #271792

    Hi,

    I ran some DMV queries to get a server's health and came across some questions..

    * The signal waits query gave almost 20% for %signal (cpu) waits

    * The CPU history says that SQL Server uses 1 to 0% of CPU but other processes use 10 to 30%

    * The top waits are PREEMPTIVE_OS_AUTHENTICATIONOPS, ASYNC_NETWORK_IO and PREEMPTIVE_OS_LOOKUPACCOUNTSID (I had LATCH and CXPACKET but creating an index made them disappear)

    Who can I determine what's causing the signal cpu waits and what type of waits are PREEMPTIVE_%?!

    Thanks,

    Pedro


    If you need to work better, try working less...

  • March 19, 2013 at 6:05 am

    #1598376

    Other extra information....

    I don't have access to the machine just the SQL instance.

    The SO admin said there are other instances on the server.

    The server has 16 cores (4 physical) and 56GB RAM. My instance has a limit of 8GB.

    Thanks,

    Pedro


    If you need to work better, try working less...

  • March 20, 2013 at 7:42 am

    #1598896

    Do you have performance problems on the server? Given that you are using only 1% of CPU, I would be surprised if you did. And if you DO, it almost certainly isn't because of CPU problems. I would look for locking and IO stalls as a more likely cause. waits aren't just about percentages - how many and most importantly how LONG are they taking per unit time is what counts.

    Best,
    Kevin G. Boles
    SQL Server Consultant
    SQL MVP 2007-2012
    TheSQLGuru on googles mail service

  • March 20, 2013 at 7:52 am

    #1598905

    PiMané (3/19/2013)

    * The CPU history says that SQL Server uses 1 to 0% of CPU but other processes use 10 to 30%

    What else is running on the particular server?

    _____________________________________
    Pablo (Paul) Berzukov

    Author of Understanding Database Administration available at Amazon and other bookstores.

    Disclaimer: Advice is provided to the best of my knowledge but no implicit or explicit warranties are provided. Since the advisor explicitly encourages testing any and all suggestions on a test non-production environment advisor should not held liable or responsible for any actions taken based on the given advice.

  • March 20, 2013 at 8:16 am

    #1598924

    There is 2 other SQL Server instances. One has 100 databases of an ERP software.

    Can the cpu signal waits be related to the ERP databases be more demanding on CPU an allocate more CPU to them?

    Thanks,

    Pedro


    If you need to work better, try working less...

Viewing 5 posts - 1 through 4 (of 4 total)

You must be logged in to reply to this topic. Login to reply