Hyperthreading Hurts Server Performance?

sebFlyte writes "ZDNet is reporting that enabling Intel's new Hyperthreading Technology on your servers could lead to markedly decreased performance, 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.'"