By default, every dedicated Mac server at MacStadium includes a headless HDMI adapter to enable GPU acceleration in macOS. This small accessory cause the operating system to believe that a display is attached, therefore making the GPU work harder to provide a smooth remote desktop experience.
It's easy to confirm that the GPU adapter is attached and working correctly.
If you're using the Scaled resolution settings, you should have options for up to 1080p on your remote desktop.
If you see something other than fit Headless (or suspect it's not working as expected), we request you open a remote hands support ticket for your local data center technicians to review and/or replace the existing GPU adapter.
This guide was written using Apple's Screen Sharing to connect with a remote Mac mini running macOS 10.12 Sierra. Your experience may differ slightly based on your software tools and versions.