Do you wish to analyse the performance of your layers within a map? Are your layers taking longer to render than expected? Are you about to publish your maps to ArcGIS Server and you wish to optimise their performance?
If so, help is at hand. A new tool for ArcGIS 10 and ArcGIS 9.3.1 has recently been released which allow you capture performance information. The tool, PerfQAnalyzer, integrates into ArcGIS Map (or it can be run as a stand-alone ArcGIS Engine application) which helps by allowing you to analyse on a layer-to-layer basis the performance of your desktop application. Furthermore, the workflows captured within the tool are fully automatable and can be scripted and executed simply at the command prompt or within ArcMap.
The PerfQAnalyzer tool is a free, unsupported, downloadable tool. More information about the PerfQAnalyzer can be found in the following blog article http://blogs.esri.com/esri/supportcenter/2012/04/03/new-arcgis-performance-calibration-tool/ which also contains links to download the tool.