The Performance can be helpful for testing a patch before applying it to a system.

A good patch fixes something broken in an OS or application. A bad patch typically fixes something but breaks something else. One evidence of a bad patch might be that applying it creates a memory leak on your system. By installing the Performance Console on a system, baselineing its memory usage, and then installing the patch and monitoring it some more, memory leaks caused by bad patches can be diagnosed fairly easily and before they cause serious problems for your production systems.

Article written by MyComputerAid.com