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londons_explore

Days of lag-free mice are well and truly over...

(Sitting here running wayland, where the mouse feels stuck in molasses!)

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(Sitting here running Wayland aswell, where the mouse feels just fine)

I wish I had a problem with mouse on Wayland, but it doesn't run for me at all

(Sat here using KDE Plasma on Wayland where the mouse lagged and glitched every time you opened a program.)

I think later versions fixed this one, though.

Which compositor are you using?

If it's Gnome, the very recent release 45 has improvements running the cursor in a separate thread.

I personally run KDE and agree that you can feel a difference between the X11 and Wayland session but it's not terrible.

Might be worth it to check that you have the "Adaptive" acceleration profile with a positive pointer acceleration value set in your mouse settings.

Check your display refresh rate. I had issues on Linux with it not supporting the maximum HDMI bandwidth properly so it drops the refresh rate to 30Hz which makes mice super laggy.

That's not a Wayland issue. It may be a specific Wayland bug that affects you, but the architecture of the system does not force any extra delays.

Imagine we are half way through sending a frame to the display.

The cursor is in the bottom half of the screen.

If I move the cursor, that should be represented in the frame that's being currently outputted, not the next frame.

Wayland has no support for that, by design.

The end result is that there is always a delay of at least one Frame.

There are ways to solve that and it’s not an architectural flaw. You just need prediction in the compositor to adjust the location of the mouse.

But honestly, the difference of a frame of latency is ridiculously difficult to feel and we’re talking about a half frame of latency here on average. It’s almost likely something else considering the entire end to end latency here is closer to 50-100ms on most systems and still isn’t what people would describe as laggy. Usually it’s some kind of software bug/hiccup that interrupts things to not be rendered at a constant tick rate or just getting hung and not processing events in a timely fashion.

There's a big difference between slow as molasses and one frame of 16ms (which you sacrifice in exchange for no screen tearing). Unless you're really into high rank competitive shooters, I doubt you can even tell that 1 frame delay is happening.

Also, make sure you use the right config - there are actual issues with some competitors which are not Wayland architecture issues. For example https://github.com/swaywm/sway/issues/4763

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