When connecting to a compatible Mac using High Performance Screen Sharing, Screens can use HEVC video streaming to deliver smoother graphics, improved image quality, and remote audio.
However, even when your Mac supports High Performance and Smooth Video & Audio is enabled, network conditions may prevent streaming from working properly.
When this happens, Screens automatically reconnects using standard framebuffer rendering to keep your remote desktop session usable.
What happens when streaming is unavailable?
Screens continues using High Performance Screen Sharing, but switches to the same type of screen updates used by Standard mode.
You still benefit from:
- Dynamic desktop resizing.
- Virtual displays.
- Display privacy, which blanks the remote Mac's physical displays when connecting as the logged-in user.
- Built-in connection encryption.
The only features unavailable are HEVC video streaming and remote audio.
Why does this happen?
1. Slow or unstable network connection
High Performance video streaming requires a fast, stable connection with consistently low latency.
Apple recommends 75 Mbps for a single 4K display, preferably over a wired network. Lower resolutions may require less bandwidth.
Even when your Internet connection seems fast, limited upload bandwidth on the remote Mac's network, congestion, or packet loss can affect streaming quality.
For more information, see Apple's High Performance Screen Sharing recommendations.
2. UDP streaming cannot be established
HEVC video and remote audio use UDP, which must be supported by the network connection.
Some networks, including certain cellular networks, VPNs, and restrictive firewalls, may prevent Screens from establishing the required UDP connection.
If streaming cannot start within the allowed time, Screens automatically reconnects using framebuffer rendering.
This ensures that you can continue using your remote Mac even when video and audio streaming aren't available.
Why is streaming paused for 24 hours?
When Screens detects that HEVC streaming cannot be established or performs poorly, it temporarily disables Smooth Video & Audio for that connection.
This prevents repeated connection interruptions caused by attempting to use streaming under unsuitable network conditions.
Streaming is automatically available again after 24 hours, allowing Screens to try HEVC on your next connection.
During this period, High Performance remains available with framebuffer rendering.
How can I try streaming again?
If your network conditions have improved, you don't need to wait 24 hours.
You can reset streaming in either of these ways:
- From your connections: Click or tap the slashed lightning bolt icon on the affected connection to reset streaming.
- From connection settings: Edit the affected connection, open Display, and reset streaming from the Smooth Video & Audio setting.
Screens will attempt to establish HEVC video and remote audio again the next time you connect.
If streaming continues to fail, Screens will automatically reconnect using framebuffer rendering.