"It's ironic," said Ibbotson. "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 when running Citrix and our software on the same server.”
HT likely fits much better on the desktop, where this type of scenario is seldom seen. It may be of interest to those who use suites like Vmware, however. Intel has not yet responded to the findings.