The Performance Meters window provides low-level metering of the digital signal processing taking place inside Ardour. One of the scenarios where this is useful is when you need to determine whether Ardour is in charge for excessive xruns.

This window displays worst case scenario measurements that do not necessarily match the DSP meter in the top right corner of the window. To see average and standard deviation values, hover either the Engine or the Session values with the mouse pointer to see the tooltip.