The process of collecting performance data has two impacts on the performance your application which you cannot control.
You can use the “Stop Collecting” and “Start Collecting” toolbar icons to control the collection of performance related data. These icons are shown below.
Clicking the red icon stops data collection. Clicking the green icon starts data collection.
Data collection can also be enabled or disabled when an application is launched by enabling or disabling the Collect data from application check box.
Important: If you close your application with data collection disabled, the next application launched will be launched with data collection disabled.
When performance data is not collected your application continues to execute the instrumented (or sampled) application, but no performance data is collected. Thus your application runs at close to normal speed and doesn’t use any memory to store the performance statistics because the performance statistics are not being collected.
Stopping and starting data collection can be a very useful technique for collecting performance data you are interested in without paying the penalty for collecting performance data up until the time you need to.
For example: Consider a 3D CAD application that you want to profile the time taken to extrude a surface and add a boss to the extrusion. You could launch the 3D CAD application with data collection turned off, create a new 3D component and manipulate the component until you are ready to extrude the surface. At this point you would click the green icon to enable data collection, then using the 3D CAD application, extrude the surface and add a boss to the surface. Using Performance Validator you could then click the red icon to disable data collection, then close the 3D CAD application. The 3D CAD application only collects performance data during the period when data collection is enabled.