The OS Processor Time (Percent) alert provides the percentage of CPU time used by all processes on the computer hosting your SQL Server instance. The WMI object Win32_PerfRawData_PerfOS_Processor property PercentProcessorTime is measured to get percent processor time.

Reduce OS processor time

If this value regularly exceeds 75%, you should take action such as:

• Reduce the number of SQL re-compilations since they are CPU intensive. There are many reasons that an object such as a stored procedure is recompiled and you can remove most of these reasons by careful coding. See the SQL Re-compilations counter for ways to dramatically reduce recompiles.
• 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.
• Stop unnecessary programs (such as the Print Spooler or activities such as the database server acting as either a BDC or PDC) from running.

Reasons why the CPU Usage metric has no value

SQLdm is unable to collect the corresponding counter due to one of the following reasons:

• It usually takes two refreshes to begin populating the CPU Usage metric, which occurs within a few seconds.
• OS Metrics collection is disabled or not working properly. You must enable OS Metrics collection for SQLdm to collect hardware performance metrics.
• Lightweight Pooling is enabled. SQLdm cannot collect OS metrics if Lightweight Pooling is enabled on the SQL Server instance.
• Alerts are disabled. SQLdm displays an alert status when at least one of the three alerts is enabled.
• The counter does not exist on this SQL Server instance.

SQL  Diagnostic Manager identifies and resolves SQL Server performance problems before they happen. Learn more > >