Intel had stated that hyperthreading"s performance advantages would show once threaded software became available, but it appears that in some cases the opposite is true. Intel"s Hyperthreading Technology (HT) is being blamed for server performance problems.With both SQL Server and Citrix Terminal Server installations, HT-enabled motherboards show markedly degraded performance under heavy load. Disabling HT restores expected levels, according to reports from within the IT industry.
"Our customers were complaining about much worse performance than expected when running Citrix Terminal Server and our software on the same machine," said Peter Ibbotson, technical director of UK accounting software company Lakeview Computers. "We"ve had fun and games in the past when we"ve enabled hyperthreading for testing and we"d seen that motherboards had started to arrive with it enabled. When we disabled hyperthreading, performance went back to normal," Ibbotson added.