The SQL Server CPU Usage (Percent) metric calculates the percentage of CPU time used by the SQL Server instance. This value is calculated by the percentage of time in a query spent by the I/O, idle, and CPU times on the computer that hosts the SQL Server instance.

To track this metric, use the CPU Usage chart in the CPU dashboard of the Server Overview tab.

Lower SQL Server CPU usage

If this value regularly exceeds 75%, consider taking the following actions:

• Reduce the number of SQL re-compilations, as they are CPU intensive. There are many reasons that an object such as a stored procedure is recompiled. You can remove most of these reasons by careful coding.
• Make sure that all T-SQL statements (whether in a Stored Procedure, Trigger, or Ad Hoc statement) that reference objects fully qualify the object referenced.

For example: SELECT * FROM Northwind.dbo Employees is a fully-qualified object reference whereas SELECT * FROM Employees is a poorly-qualified object. You can reuse the execution plans of fully-qualified objects "as is," whereas plans where you either cannot reuse the not fully-qualified objects or, if they are reused, then they are subject to a highly restrictive COMPILE lock while SQL Server determines if all of the objects referenced in the T-SQL code have the same owners as the execution plan currently in cache. Both of these situations consume a significant amount of CPU time.