KWin-LowLatency: An Effort To Yield Less Stutter & Lower Latency With The KDE Desktop

[R41N3R]

I agree with the comments of several others, ideally we need to get a low latency Kwin based on Wayland and Vulkan.

[boeroboy]

I use Compiz with my KDE and I'm wondering how this will effect the experience potentially. Compiz already gives options to specify fps, vsync, and use direct/indirect rendering. Anybody know? Some Compiz effects can cause latency but I'm fairly sure those are plugin responsibility.

[RealNC]

Compositing not being driven by vsync has always been a huge ugly wart of Linux desktops. On Windows and macOS this has been the case for a long time now and the desktop never skips a beat there. Video plays back perfectly and so do games. On Linux, video playback is really problematic on high refresh rate displays. Watching 50FPS Formula 1 races for example on a 100Hz display can only be described as an embarrassment on Linux. I have to disable compositing. On Windows and macOS it's perfect.

What I find disturbing is the attitude of some of the developers who work on the Linux compositors. They don't even recognize this as a major problem.

I hope this fork won't die and that support for this will make it into Wayland.

[royce]

A big problem is that developers have the hardware they have, and often this is bog-standard 60hz 1080p single screen setups.

[Damnshock]

I use Compiz with my KDE and I'm wondering how this will effect the experience potentially. Compiz already gives options to specify fps, vsync, and use direct/indirect rendering. Anybody know? Some Compiz effects can cause latency but I'm fairly sure those are plugin responsibility.

If you use compiz you are not using kwin, thus this doesn't affect you at all. Besides, it's a fork, it only can affect you if you actively switch to it

[cl333r]

... It is sad to see this kind of stupidity in the Linux community as a pro software developer.

It's not a Linux community stupidity, it's how humans tend to work, it's about company logistics and personal bias and motivation. I've reported like 10 bugs in my life to different apps and none of them was addressed. And in forums issues are usually ignored as "anecdotal evidence" because "it works fine for me and my friends so it can't work bad anywhere else".

Speaking of KWin: I do use it all the time for years and it feels much slower than Gnome (but Gnome is developed by people with mental issues, so I can't use it) - take this "anecdotal evidence".

[M@GOid]

On Linux, video playback is really problematic on high refresh rate displays. Watching 50FPS Formula 1 races for example on a 100Hz display can only be described as an embarrassment on Linux. I have to disable compositing. On Windows and macOS it's perfect.

Strange, here works fine. What is exactly the problem? What is your setup? I use a AMD card with radeonsi driver, VLC video player and KDE to watch F1 races on my PC (using a PixelView USB adapter), but here is a 60Hz broadcast and I use a 120Hz Benq monitor.

[M@GOid]

A big problem is that developers have the hardware they have, and often this is bog-standard 60hz 1080p single screen setups.

Indeed. When I got my 120Hz monitor years ago, KDE compositing was locked to 60 fps, instead of what the monitor was operating at the time. I had to use a modified config file to enjoy the fluidity that only a high frequency monitor can provide. Also, the AMD drivers were also problematic, making my then Radeon 290 operate at high frequencies and above average temps.

Also, people with high dpi monitors to this day still suffer from the bogus 21/24 inch, 1080p standard that even Linux Torvalds was complaining about a couple years ago.

[schmidtbag]

What exactly is resulting in the stuttering? My crappy i3 Haswell laptop with integrated graphics works very smoothly with kwin+Wayland, even with the compositing effects and high CPU load. Although I don't think a Vulkan compositor needs to be a high priority, I do think it's a better idea than whatever else they intend to do to improve latency.

Wayland will always be useless for gaming so long as they keep forcing Vsync, with no way to disable it.

The fact that Wayland and Gnome developers thought it would be okay to force Vsync and even hard cap the refresh rate to 60Hz (only recently fixed in Gnome), makes me have almost zero trust in them for gaming performance.

Speak for yourself. Even though my gaming PC uses X11, I deliberately keep vsync on because I prefer a tear-free experience over input latency. Sure, a hard cap of 60Hz is dumb (assuming your display goes higher) and I agree there should be a [user-friendly] way to disable vsync, but you are heavily exaggerating your preferences as though they're what everyone else prefers.

[Mario Junior]

Holly shet, finally! Finnaly someone will make something about this problems on Kwin. I already reported in another thread about my experience with Plasma on AMD GPU. Kwin needs a rework urgently!