Setting the Measurement Accuracy 
To set the measurement accuracy, choose Settings .
You go to a dialog box.
You can choose between:
High
This accuracy level uses a platform-specific high-resolution clock. This resides in a special part of the host. This option reduces the probability of measurement results being incorrect. However, if you use high-resolution measurement, the maximum measurement interval is shorter. The activating ABAP statement is: SET RUN TIME CLOCK RESOLUTION HIGH.
Low
This option uses a lower resolution. Consequently measurement errors are more likely. However, low resolution has a greater maximum measurement interval. The activating ABAP statement is: SET RUNTIME CLOCK RESOLUTION LOW.
Note
When you record times, remember that the absolute times returned are unreliable in the following circumstances:
For some multiple processor machines if a processor switch occurs. See the syntax documentation for the statement SET RUN TIME CLOCK RESOLUTION in transaction ABAPHELP for this.
On single-processor hosts when the clock rolls over.
Recommendation
We recommend that to obtain a representative runtime measurement, you execute some pre-runs of your application to fill buffers and to avoid program generation in your true measurement.
The clock interval specifies the time in seconds before the clock rolls over.
To display the default clock interval, choose .