CPU Performance

Context switching: This occurs when threads are switched between CPUs in your SQL Server, and excessive context switching eats up CPU resources. In some cases, context switching can be reduced by turning on Lightweight Pooling. See this website for more details on this option.

Recompilation: Excessive SP recompilation wastes CPU resources and slows SQL Server. See this website for ways to reduce SP recompilation.

Sorting: At some point, data may have be be sorted. But to reduce the load sorting can have on SQL Server, only sort the minimum amount of data that needs to be sorted, or consider pushing off the sorting function onto the client.

Hashing: Hashing often occurs when JOINs are used. They are also used in UNIONs. Often, but not always, a HASH JOIN can be modified so that is runs as a LOOP JOIN instead, which reduces CPU activity and speeds performance. See this website for more details on LOOP JOINs.