Screen share lag

Hello bayme96,

After reviewing your post, it sounds like screen sharing is slow only when connecting using a retina display. There are some screen sharing preferences that may help if you change these.

"Choose Screen Sharing > Preferences, then set the following options:

• Under Display, select “Scale to fit available space” or “Show full size,” depending on how large your screen is and how much of it you want to use for the shared screen. This option changes the default behavior for when you share the screens of computers you’ve never connected to before. To change the current scale, choose View > Turn Scaling Off or View > Turn Scaling On.

• Under Display, select a “Scroll the screen” option to determine how the screen sharing window behaves when you move the pointer. To decide which option you want, try each one by selecting it and then moving the pointer around in the window.

• Under Quality, select “Adapt quality to network conditions” to view the shared screen more quickly, or “Show the screen at full quality” for a more detailed view of the shared screen. This option changes the default behavior for when you share the screens of computers you’ve never connected to before. To change the current scale, choose View > Adaptive Quality or View > Full Quality.

• For the best results, and if your Mac is connected to a fast network, view the screen at full size and show the screen at full quality."

Share the screen of another Mac

Please don't hesitate to let us know if the steps resolved your issue or if you need additional assistance.

Thank you for using Apple Support Communities. Have a nice day.

Hey bayme96,

Thanks for the update. Since this began after updating to Catalina, try booting into safe mode and see if the issue persists.

"If the issue continues in safe mode

If the issue continues while in safe mode, or your Mac restarts several times and then shuts down while starting up in safe mode, you should reinstall macOS and make sure that your Apple software and third-party apps are up to date.

If the issue doesn't continue in safe mode

If the issue doesn't continue while in safe mode, leave safe mode by restarting your Mac normally. Then test for the issue again. The issue might be resolved.

If the issue returns after leaving safe mode, startup items are probably at fault. Apps can install such items in numerous places, and they aren't always easy to find or recognize. For that reason, you should first make sure that you've installed any available updates for your Apple software and third-party apps.

If updating your software doesn't help, try any of these solutions:

• Test your login items
• Test with another user account
• Unplug all accessories from your Mac, including printers, drives, USB hubs, and other nonessential devices. You could have an issue with one or more of those devices or their cables.
• Reinstall macOS

If you still need help, please contact Apple Support."

How to use safe mode on your Mac

Have a good one.