FPS is not the same as original monitor + minor mouse input delay

[AmrSol]

Hi waydabber,
I'm using a Dell S2721D 27" QHD 75fps screen and a Logitech MX Master 3 mouse.
I've noticed that when BetterDummy is being mirrored onto my monitor, the FPS of the monitor is capped at 60. Is it possible for the FPS to be uncapped?
Also, I've noticed that there is a slight mouse input delay. The mouse does not feel as accurate when BetterDummy is in use.

Of course, I would like to thank you for your amazing app. It is absolutely shocking that Apple is rendering so many monitors "unenjoyable" to use.
Looking forward to your response. Feel free to ask any questions.
Kindest regards,
Amr

[waydabber]

Hi @AmrSol - yes, virtual screens (like SideCar, AirPlay, DisplayLink and also BetterDummy) are maxed out at 60Hz in macOS. This is a limitation that might change in the future (the relevant APIs do accept higher refresh rate configurations but don't act on it) maybe when Apple introduces ProMotion for Sidecar or AirPlay.

See this for more info: #140

[AmrSol]

Thanks @waydabber,
Any advice on the mouse issue?
Amr

[waydabber]

I am not sure to be honest. I do not percieve any extra lag and technically there should not be any when mirroring on Apple Silicon as what is happening does not tax the system at all (also there was this guy who did some tests about it). However 60Hz is inherently somewhat slower than a higher refresh rate and it is possible that you can tell the difference. Also the MX on bluetooth uses a weird polling rate (I have an MX 3 for my PC which I sometimes use with the Mac) that is not in sync with a 60Hz display (at least that is my impression) which results in a jumpy/inaccurate cursor. This is rather annoying but is the problem of this line of Logitech mices. This issue might not be that pronounced with a 75Hz display (I don't have an experience with that).