| Highest | Lossless, 60 fps, full resolution. Thunderbolt only. |
|---|---|
| High | Full resolution, the sharpest compressed picture. Smoothness depends on your Mac. |
| Medium | Full resolution, sharp text once the picture settles. |
| Low | For slow Wi‑Fi. Half resolution, 30 fps. |
Low, Medium and High are compressed on every connection, also over Thunderbolt. Highest is the lossless picture.
The speed test
During setup, and whenever you ask, Second Display tests the connection for about five seconds and marks one level Recommended. Until you choose a level yourself, the display follows the recommendation, also after later tests.
To test again, open the display’s Quality menu and choose Test Connection…, or click Test Now in Settings › Connection.
Choose a level
Pick a level in the display’s Quality menu, or in Settings › Connection. Each display has its own. A level the connection can’t carry says why, for example “Highest needs a Thunderbolt cable.”
Over Wi‑Fi, when the connection gets slower, the menu may suggest a lower level: “Your connection got slower. Switch to Medium?”