For best results...

If you have a large amount of data, the profiler output could be very large or unmanageable. For this reason, it is best to profile only a subset of the original data.
You can reduce profiler output by specifying a time limit so that nothing is reported until it exceeds the time limit that you specify. See section Configuring the Map Profiler for details.
When running the profiler, always limit or terminate other processes running on your machine to avoid adverse results.