To interpret performance counters and execution statistics correctly, it is necessary to know state of Hyper-Threading. In principle, at low overall CPU utilization, for non-parallel execution plans, it should not matter whether HT is enabled or not. Of course, DBA life is never that simple. The state of HT does matter at high over utilization and in parallel execution plans depending on the DOP. SQL Server does seem to try to allocate threads on distinct physical cores at intermediate DOP (DOP less...(read more)