[KLUG Advocacy] More on Hyperthreading goodness

Chester Wisniewski chetw at zuzax.com
Sat Nov 19 20:10:38 EST 2005

    I recall a brief email banter a while back where I suggested 
hyperthreading was detrimental and Adam and I jousted back and forth a 
bit... more info from a slashdot article citing Microsoft and Citrix

/"ZDNet is reporting that enabling Intel's new Hyperthreading Technology 
on your servers could lead to markedly decreased performance 
<http://news.zdnet.co.uk/0,39020330,39237341,00.htm>, according to some 
developers who have been looking into problems that have been occurring 
since HT has been shipping automatically activated. One MS developer 
from the SQL server team put it simply: 'Our customers observed very 
interesting behaviour on high-end HT-enabled hardware. They noticed that 
in some cases when high load is applied SQL Server CPU usage increases 
significantly but SQL Server performance degrades.' Another developer, 
this time from Citrix, was just as blunt. 'It's ironic. Intel had sold 
hyperthreading as something that gave performance gains to heavily 
threaded software. SQL Server is very thread-intensive, but it suffers. 
In fact, I've never seen performance improvement on server software with 
hyperthreading enabled. We recommend customers disable it.'"


More information about the Advocacy mailing list