Why would enforcing vsync add more than 1/60s of latency to anything?
This looks way more like badly designed animations than some fundamental problem coming from the hardware.
Desktop compositing latency is real
11–20 of 306 posts
Re: Desktop compositing latency is real
#12That's why I prefer to play games in fullscreen as opposed to "borderless windowed", I have noticed quite a bit of input lag in the latter mode.
Re: Desktop compositing latency is real
#13The data speaks for itself but I'm trying to perceive any latency in my Firefox (win10) and unable to. Typing seems instantaneous to me. I hate the milliseconds the start menu takes to animate though. Win7 start was instant.
> Typing seems instantaneous to me.
When the only source of latency is the extra ~16ms added by the composting, you likely can't feel it, but it adds up to other sources of latency that can make things feel bad more often. Such as:
-latency added by text editors depending on their quality and the amount of work they are doing (colors, intellisense, file size, etc).
-latency added by keyboards, some are worse than others
-latency added by monitors. Good ones are in the 1ms range but bad ones can be as high as 40
Sadly the latency on all of these fronts has generally been trending higher as computers have gotten more powerful.
Re: Desktop compositing latency is real
#14I would like to see end-to-end measurements (=high speed camera footage analysis) before making final conclusions. Not saying that compositing doesn't add latency, but I feel like the system is so complex that this sort of userspace software measurement might not tell the whole story
Re: Desktop compositing latency is real
#15Well his website is entirely ruined by how close the text is to the left side. It's like closer than margin:0 close.
Re: Desktop compositing latency is real
#16No left margin on webpages is real too, and it annoys me
Are you on mobile? It centres perfectly fine for me on desktop. The linked CSS file uses this method:
body {
max-width: 844px;
margin-left: auto;
margin-right: auto;
font-family: Verdana, Arial, Helvetica, sans-serif;
}
Re: Desktop compositing latency is real
#17The data speaks for itself but I'm trying to perceive any latency in my Firefox (win10) and unable to. Typing seems instantaneous to me. I hate the milliseconds the start menu takes to animate though. Win7 start was instant.
What I hate even more is when I press the Windows key and start typing an application's name into the Start menu textbox, and it misses the first two or three keypresses.
Re: Desktop compositing latency is real
#18That's why I prefer to play games in fullscreen as opposed to "borderless windowed", I have noticed quite a bit of input lag in the latter mode.
It depends on the game for me, usually I prefer borderless windowed because I tend to alt-tab out a lot.
Re: Desktop compositing latency is real
#19I recently measured it with my phone's camera in slow motion mode. The system is an AMD Ryzen 1800X with AMD R9 280x GPU, KDE Plasma with KWin window manager in compositing mode. Key press to screen output latency was ~33 millseconds (90 fps recording, so increments of 11) in KWrite. The computer feels plenty responsive with that latency, and I hate latency... It is a full stack real world result - for comparison pur…
How are you measuring from key activation?
Re: Desktop compositing latency is real
#20I recently measured it with my phone's camera in slow motion mode. The system is an AMD Ryzen 1800X with AMD R9 280x GPU, KDE Plasma with KWin window manager in compositing mode. Key press to screen output latency was ~33 millseconds (90 fps recording, so increments of 11) in KWrite. The computer feels plenty responsive with that latency, and I hate latency... It is a full stack real world result - for comparison pur…
33 ms is two frames, if your monitor is at 60 Hz. If you tried vscode or other electron app, it might be 49 ms (3 frames). These are the numbers I'm getting from 1900X with Nvidia 1080 GPU, Gnome3, 4k@60hz, but without measuring latency of the keyboard itself.
Modern keyboards are another part of the problem. They can also take their sweet time since keypress until packet appears at the USB bus. See https://danluu.com/keyboard-latency/