THE SQL Server Blog Spot on the Web

Welcome to SQLblog.com - The SQL Server blog spot on the web Sign in | |
in Search

Merrill Aldrich

Poll: Hyperthread or not on 2 x 4 core Nehalem SQL Server?

Common wisdom with previous generations of server hardware was that SQL Server might not benefit from hyperthreading or could be degraded at high CPU usage; does anyone have definitive data about Nehalem (non-EX) servers and SQL Server 2005 or 2008?

Here are some resources:

http://support.microsoft.com/kb/322385 

http://sqlblog.com/blogs/kevin_kline/archive/2007/08/18/the-perils-of-hyperthreading-for-sql-server.aspx

http://blogs.msdn.com/slavao/archive/2005/11/12/492119.aspx 

http://technet.microsoft.com/en-us/magazine/2007.10.sqlcpu.aspx 

http://serverfault.com/questions/33515/current-wisdom-on-sql-server-and-hyperthreading 

I am wondering whether Nehalem changes this story at all.

[Follow up 2/12/2010: I tested, and did some further reading, and decided to split the difference on this: transactional systems that have high numbers of connections and small queries have HT enabled, and our reporting/warehouse system that does fewer but more complex queries has it turned off.]

Published Thursday, January 14, 2010 3:05 PM by merrillaldrich

Comment Notification

If you would like to receive an email when updates are made to this post, please register here

Subscribe to this post's comments using RSS

Comments

 

Denny Cherry said:

The newer processors shouldn't have any impact on HyperThreading as it is still CPU sharing and those cycles have more important things to do.

January 14, 2010 5:42 PM
 

Glenn Berry said:

The Nehalems (Xeon 5500 series) seem to perform better with OLTP workloads with HT enabled. Every TPC-C and TPC-E benchmark submission I have seen has HT enabled for this CPU.

I have it enabled on my Xeon 5550 production server, with very good results. You should test it with your workload.

January 17, 2010 1:38 PM

Leave a Comment

(required) 
(required) 
Submit

This Blog

Syndication

Powered by Community Server (Commercial Edition), by Telligent Systems
  Privacy Statement