CPU requirements

The CPU is one of the most important determinants of performance. The following are guidelines associated to choosing the correct CPUs:

• Validate the Operating Systems (OS) restrictions on the number of CPUs.

  For CPU restrictions for current Windows releases, refer to the Memory Limits for Windows and Windows Server Releases page on the Microsoft MSDN web site.

• Validate the Microsoft SQL Server database software licensing restriction on the number of CPUs.

• The CPU performance target is to have less than 30% average CPU usage. CPU usage is based on 100% – (% Idle Time). For example, if the % Idle Time = 75%, then CPU usage is considered to be 25%.

  If you take the CPU Time for Idle Process and divide by the running time of the machine, you will get the average percent idle time. The average CPU usage is just one minus the average idle time.

• To use the Task Manager to view the CPU Time: Select Processes > View menu > Select Columns and choose the CPU Time column.