The HDMI Forum, responsible for the HDMI specification, continues to stonewall open source. Valve’s Steam Machine theoretically supports HDMI 2.1, but the mini-PC is software-limited to HDMI 2.0. As a result, more than 60 frames per second at 4K resolution are only possible with limitations.
Do you have adaptive sync on? If you do try turning it off for both monitors. That worked for me but your milage may vary.
Mint isn’t wayland yet and X11 does not support adaptive sync if multiple monitors are connected
I don’t even know what that is, frankly.
It’s a generic term for Freesync/GSync, having a variable refresh rate.
Oh. No, my monitors should always be at 60Hz now. They’re both DC powered (internal + USB).