Yes, the UGREEN USB-C to DisplayPort 1.4 cable is compatible with a Samsung Odyssey G9 49" display and a MacBook Air M1, subject to certain conditions.

- The cable requires that the USB-C port on your MacBook Air M1 supports the "DP Alt Mode" function or is a Thunderbolt 3/4 port.
- You must configure your monitor to operate at a frame rate of 60Hz initially, and disable adaptive sync to achieve the maximum resolution of 5120x1440.
- The cable supports DisplayPort 1.4 with Data Stream Compression (DSC), enabling high resolutions and frame rates to be maintained.