MAXDOP and Hyperthreading | SQL Server Performance Forums

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MAXDOP and Hyperthreading

I have a PE 6600 with 4 CPU and Hyperthreading. I’d like to know how to decide which 4 cpu should be selected when configuring the SQL server through EM in order to select the 4 physical ones. Andrea

unless you have alot of resources to validate each individual query, i would turn off HT
I would also review the following;en-us;329204;en-us;322385
Well, I’m running SQL 2000 SP 4 on Win 2003 server so I think maybe Hyperthreading is not necessarily to be discarded. After turning processors 4,5,6,7 off and setting the max CPU used for parallel queries the performance on large jobs has decreased a bit and I couldn’t prove that the performance of small queries has actually gotten better.
So I’m thinking of re-enabling all the CPU and use perhaps 7 out of 8 CPU for parallel execution.
Also, even after reading the articles mentioned above, I couldn’t figure out how to enable the 4 physical processors as opposed to the logical ones so in doubt, I think it’ll be best to turn them all on again.
Any advice?

May check this link. HTH Satya SKJ
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