Hyperthreading Hurts Server Performance?

The code wasn't changed
(Score:5, Informative)
by ocelotbob (173602) Alter Relationship on Saturday November 19, @08:22AM (#14070290)
(http://www.ocelotbob.org/)
I read the intel assembly guide section regarding hyperthreading, and it clearly states that performance will drop if you don't take the shared cache into consideration. The two logical threads contend for the cache, causing the performance problems that were described. In order for there to be a true benefit to hyperthreading, either the program, the OS or the compiler needs to determine that hyperthreading is enabled, and model the code to only use less than half the cache. It's been known that way since the beginning, and frankly, is silly that MS is scratching their heads wondering why this is. Lower the cache footprint, and I'll be willing to bet that performance rises dramatically.
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Marxism is the opiate of dumbasses
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