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We have a server with 2 quad xeon 5550 processors. The only application installed on the server is SQL server. CPU usage rarely goes above 40%, and the transaction rate is 2,000 transactions per second.

Processor queue length is also about 2. Everything seems normal, except context switches which has an average of 88,000 and max of 232,000 during work hours.

I've read in SQL server documents that a context switch number larger than 15,000 is indicative of a CPU problem. Is this actually a problem, even though the CPU counters seem normal?

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What do your instance's wait stats look like? sqlskills.com/BLOGS/PAUL/category/Wait-Stats.aspx –  Jon Seigel Feb 9 '11 at 2:13

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I see that's a Nehalem processor with hyperthreading.

The last time we asked the general consensus was to disable hyperthreading by default on a SQL Server specific box (and we disabled it on ours, with good results). Browsing around a few other sites, I'm hearing that advice echoed by other reputable folks.

So, you might try turning off hyperthreading first, then re-measuring.

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I think the testing both ways is the most important step. From what I recall of the discussion and from what we've seen ourselves it varies based on workload - some things do well with hyperthreading, others... not so much. –  RobM Feb 7 '11 at 9:19

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