The line updates while the menu is open. It shows:

  • The stream: Raw for the lossless picture over Thunderbolt, HEVC or H.264 for a compressed one.
  • The frame rate the display really shows, or “no motion” while nothing on the screen changes.
  • The delay from your Mac to the display, in milliseconds.
  • The bit rate, for a compressed stream only: “HEVC · 58 fps · 34 ms · 41 Mbit/s”.

The line is on by default. To hide it, turn off Show statistics in the menu in Settings › Advanced.

On the display itself

Show statistics overlay, also in Settings › Advanced, shows the frame rate, the delay and more in a corner of the display’s picture.

Check Smoothness

In Settings › Display, Check Smoothness… moves a test pattern across the display for about 10 seconds while it measures. Nothing flashes, and Esc stops it. The result says Smooth, Mostly smooth or Choppy, with one piece of advice when there’s something to try, such as a Thunderbolt cable or a lower quality.