KDE isn't very smooth on good hardware, what gives?

blackout23 · 2013-05-05 10:30:56

Usually VSync introduces input lag. That's in the nature of Vsync try turning it of in the KWin settings.
That's why hardcore gamers buy 120 Hz monitors, because VSync adds a tiny handicap in fast paced shooters.

Last edited by blackout23 (2013-05-05 10:32:25)

smakked · 2013-05-05 10:45:00

gedgon wrote:

smakked wrote:
but in reality who moves windows around that fast ?
It's not about moving windows, it's about lag, which is "everywhere", again, the same example http://youtu.be/nNK0YIqawuY but I understand that this is not a problem for most people.

Yeah doesnt bother me, just installed Nvidia driver and it is actually alot more noticeable then the opensource variant.

blackout23 · 2013-05-05 10:51:50

I tried it out. It's just VSync doing its job as I expected.

smph · 2013-05-05 11:54:15

Since I have both Windows 8 and Arch Linux installed on the same machine I can report the following regarding lag when dragging windows, using Radeon HD6850 (with open drivers on linux):

- X11 + Compiz standalone: noticeable lag when dragging at slow speeds
- Wayland + Weston: still noticeable lag, a bit less that X11
- Windows 8: no lag that I can see, if you try to move faster you can't see anything anyway

No tearing whatsoever in any of the cases. Not sure how indicative this is of the general lag with the graphics systems of course.

pandev93 · 2013-05-05 13:23:03

intel i5 3570k, nvidia gt670, and no lag , is so strange your problem. Probably, a driver issue

pandev93 · 2013-05-05 13:32:38

smph wrote:

Since I have both Windows 8 and Arch Linux installed on the same machine I can report the following regarding lag when dragging windows, using Radeon HD6850 (with open drivers on linux):
- X11 + Compiz standalone: noticeable lag when dragging at slow speeds
- Wayland + Weston: still noticeable lag, a bit less that X11
- Windows 8: no lag that I can see, if you try to move faster you can't see anything anyway
No tearing whatsoever in any of the cases. Not sure how indicative this is of the general lag with the graphics systems of course.

radeon 6850 with opensource drivers-.....

chord · 2013-05-05 18:09:48

@smph
radeon * (especially with opensource driver) - it is a lag by default under linux.
Also OP has nvidia with proprietary driver, so your comparison isn't correct. When radeon lags, nvidia should be smooth.

smph · 2013-05-05 20:44:13

Well, there was some talk about the general compositing performance on linux so I did the comparison mainly in reference to that. I also tried Intel integrated graphics (Ironlake) on the same machine, and with Compiz the window dragging lag was pretty much exactly the same but interestingly under Weston there was no lag whatsoever (like Windows 8).

And don't get me wrong, my desktop is actually quite smooth even when running Compiz with radeon opensource at low clocks, there's just this frame-or-two lag between the cursor movement and the screen action, not very noticeable in general use IMO.

Edit. I can also tell that resizing the same GTK3 apps is MUCH smoother on Wayland than with X11, so there is hope.

Last edited by smph (2013-05-05 21:19:09)

Odaer · 2013-05-07 22:26:18

gedgon wrote:

nuc wrote:
Nonsense. Compositing is important for fluentness and less workload because it enables hardware acceleration. Without compositing there will be tearing and unfluent window resizing because the CPU has to render it. With Hardware acceleration, the GPU does the job.
Oh, come on. I agree only with tearing. Resizing is much, much faster without compositing.

I'm have heard this earlier. For me if I resize without compositing I get heavy tearing and graphical artifacts. With compositing the tearing is gone and the artifacts disapear. Instead I get a little bit less fluent resizing but the differense is really small and as the graphical quality is so much better I think it's look much better with compositing.

I also get a little bit choppy resizing in OSX it's better than KDE but not a big difference really. I have always assumed it is a effect of clientside decoration, some sort off PID link:ish effect or somthing...

brebs · 2013-05-07 23:57:44

smph wrote:

frame-or-two lag

Seems relevant: Nvidia has a default lag of up to 3 frames, which can be changed with OGL_MaxFramesAllowed.

reflexing · 2013-05-08 10:48:44

Can you please show us the output of

qdbus org.kde.kwin /KWin supportInformation

command?

gedgon · 2013-05-08 19:18:59

Odaer wrote:

For me if I resize without compositing I get heavy tearing[...]

No one has said otherwise.

Odaer wrote:

[...]and graphical artifacts. With compositing the tearing is gone and the artifacts disapear.

I'm not sure about what artifacts are you talking. The only thing that comes to mind is XSync, but unfortunately KWin also isn't good at this. Here's a comparison with Compiz (60fps; take a look at tabs bar and scrollbar):
Compiz - 883KiB https://mega.co.nz/#!mBhylLaI!Y790Tkk0I … O0-nlz-EM4
KWin - 1.1MiB https://mega.co.nz/#!Pcgi3bQA!KO7xZ3iWz … NFAZASHWmE

brebs wrote:

smph wrote:
frame-or-two lag
Seems relevant: Nvidia has a default lag of up to 3 frames, which can be changed with OGL_MaxFramesAllowed.

Thanks for the tip, but unfortunately if there is any difference, I can't see it.

Arch Linux

#26 2013-05-05 10:30:56

Re: KDE isn't very smooth on good hardware, what gives?

#27 2013-05-05 10:45:00

Re: KDE isn't very smooth on good hardware, what gives?

#28 2013-05-05 10:51:50

Re: KDE isn't very smooth on good hardware, what gives?

#29 2013-05-05 11:54:15

Re: KDE isn't very smooth on good hardware, what gives?

#30 2013-05-05 13:23:03

Re: KDE isn't very smooth on good hardware, what gives?

#31 2013-05-05 13:32:38

Re: KDE isn't very smooth on good hardware, what gives?

#32 2013-05-05 18:09:48

Re: KDE isn't very smooth on good hardware, what gives?

#33 2013-05-05 20:44:13

Re: KDE isn't very smooth on good hardware, what gives?

#34 2013-05-07 22:26:18

Re: KDE isn't very smooth on good hardware, what gives?

#35 2013-05-07 23:57:44

Re: KDE isn't very smooth on good hardware, what gives?

#36 2013-05-08 10:48:44

Re: KDE isn't very smooth on good hardware, what gives?

#37 2013-05-08 19:18:59

Re: KDE isn't very smooth on good hardware, what gives?

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