IIRC correctly the 1% and 0.1% frame times tell you how the frame rate varies i.e. if most of the time it is running at 60FPS and every so often tanks to 1 FPS.

IIRC correctly the 1% and 0.1% frame times tell you how the frame rate varies i.e. if most of the time it is running at 60FPS and every so often tanks to 1 FPS. So some average FPS numbers might look okay but the frame rate might be tanking like every minute.