I have a system that should be pretty OK: it's a Core I7 920 with a Geforce 9800 GTX using the nVidia drivers. On this system, compiz is perfectly smooth, while kwin is very stuttery. For example, rotating the desktop cube between workspaces, kwin looks about 5 FPS, while compiz is doing at least the refresh rate of the monitor. The other effects (window resizing, etc) are also much smoother in compiz.

So I want to use compiz, but I have a problem because system settings / default applications / window manager / use a different window manager / compiz, there is a big crash and kwin is restored.

Is anyone doing this successfully, mixing compiz with the rest of KDE? I'm using whatever version of KDE that is coming with KUbuntu Natty Narwall. If you are doing such a thing, could you tell me how you got it to work?

Thanks

I wish I didn't have to do this and I would prefer to use kwin because it is easier and default, but the kwin performance is just too bad, and also the UI and options aren't as good as compiz. I hope kwin will be optimized in the future because that is what I would like to use.

which Nvidia drivers, I think 280.13 is the current

is the stuttery issue found if you create and login as a new user

you don't state version of KDE, I can tell you in openSuse using KDE 4.7 the latest version of Compiz won't run but don't know about Kubuntu

"is the stuttery issue found if you create and login as a new user"

Yep, same thing. I don't think it's a settings issue - it's just that kwin seems rather inefficient. I've found plenty of other threads about the same topic elsewhere around the internet and that seems to be the general consensus, that compiz is much more efficient.

If I'm reading this thing right, it's KDE 4.6.2. Maybe it's a similar problem. Bummer - it used to work OK with KDE on earlier versions!

Guess I'm stuck with kwin and having to shut off all the eye candy to make it run halfway decently...

which Nvidia driver? drivers do make a difference

just because Compiz and KDE 4.7 (also 4.6 iirc) doesn't run on openSuse is no reason not to query the Kubuntu forums.

"which Nvidia driver?"

Looks like 270.41.06, which is the latest one that KUbuntu 11.04 offers to install for me. Oddly, all this worked OK in prior versions. Odd!

I will check in with the kubuntu forums and see if anyone knows something about it there.

Thanks

I had a similar problem. 4.5 was very smooth while 4.6 had stuttering issues.

To solve this i edited this file:
.kde/share/config/kwinrc

Under "[Compositing]" i added:
MaxFPS=120
RefreshRate=120

(And then you need to "restart" kwin)

Sometimes it is one particular effect that is causing KWin slowness, e.g. Blur was often to be blamed. So you might consider disabling effects one by one.

Another option is to check if there is something that causes constant repainting. There is an effect in the 'Tools' section of the 'All Effects' list which colors areas according to their repaint frequency. Green is no/few repaints, red is a lot.

swe wrote:Under "[Compositing]" i added:
MaxFPS=120
RefreshRate=120

Why would you use so high values? Most screens these days have a refresh rate of 60 Hz or not?

HmpfCBR wrote:Why would you use so high values? Most screens these days have a refresh rate of 60 Hz or not?

You can use any value you like. I choose to set the value to twice the refreshrate of my monitor to get a "super smooth" experience. (The actual fps will be capped at 60fps, but using the double value will prerender frames and the output will be.. well.. smooth.)
This effect is clearly visible when using firefox plugins such as SmoothWheel.

Sometimes it is one particular effect that is causing KWin slowness, e.g. Blur was often to be blamed. So you might consider disabling effects one by one.

I've disabled blur and it didn't make much difference. It does seem related to what is being displayed on the desktops. With all desktops empty, it's OK - not quite as smooth as compiz, but good enough to use. However, with more than a few windows open, it gets real choppy where compiz remains smooth.

And it's particularly bad with a full screen window. Not maximized, but full screen. That'll make it get super choppy, but the same window almost the same size when maximized is OK.

Another one that impacts it is Thunderbird. I can open a Thunderbird window and switching workspaces gets all choppy. If I iconify the same window, it's smooth. A Firefox window of the same size doesn't cause the choppyness though.

I have the exact same problem with Kwin. It's very choppy, and it gets worse the more windows I have open.

I think I have tried almost everything suggested to fix this, but no luck. I have an Intel Core i7 860, 8 GB RAM, with nVidia Quadro NVS 295 graphics card running openSUSE 11.4 with KDE 4.7. I have the nVidia driver 275.21, but I have tried all drivers up to the latest beta.

I don't really know where to start looking for what causes this.

It's very choppy, and it gets worse the more windows I have open.

Yes! Same here. The more windows open, the choppier it is, even on high end hardware. On older hardware, (like a Geforce 7800), it's simply unusable, even though Compiz is totally smooth. Also some windows are worse than others, even when they're the same physical size.

Coincidentally enough, a friend just called me last night complaining about choppy window moving and resizing after he tried KDE (he was on gnome before). I had to tell him to turn off desktop effects.

I don't really know where to start looking for what causes this.

The fact that compiz works so smoothly even with every possible bit of eye candy turned on makes me think it isn't a problem with the hardware's capabilities or anything like that. It seems more that Kwin is doing something inefficient, although I don't know what. I really hope they work on optimizing it though. It would make for a big improvement in the usability of the KDE desktop.

I want to go back to compiz until KWin improves, but now compiz crashes on the latest KUbuntu . It's a classic open source dilemma: there are two projects to do the same thing, neither one of them usable, rather than one project that had enough effort put in to make it work well.

dasod wrote:I don't really know where to start looking for what causes this.

Since there are quite a few here who report similar problems, but also people, which have no such issues, despite they have the similar driver and hardware it might be worth to look a bit closer at the similarities and differences of the setups.

Driver, GPU, X, Kernel version (...) are all given when running

Code: Select all

kwin --replace


in konsole.

Most of kwin configuration is in "~/.kde/share/config/kwinrc".

So here is mine:
KDE 4.7.00, Kubuntu 11.04, Qt-Graphics System: Raster
kwin --replace
~/.kde/share/config/kwinrc.

KWin is not choppy at all, whith compositing enabled and quite a few (currently 15, most qt, some gtk). Am I missing something important?

Good idea HmpfCBR. I see this on every system I have ever tried it on, which is to say around 8 hardware configurations. In fact I've never NOT seen it. But here is one for the system I'm typing on now, a core I7 920.

The kwinrc is a bit long to post here and I'm not sure how to use pastebin, but here's the kwin --replace output:

Code: Select all

OpenGL renderer string:                 GeForce 8800 GTX/PCI/SSE2
OpenGL version string:                  3.3.0 NVIDIA 270.41.06
OpenGL shading language version string: 3.30 NVIDIA via Cg compiler
Driver:                                 NVIDIA
Driver version:                         270.41.6
GPU class:                              G80/G90
OpenGL version:                         3.3
GLSL version:                           3.30
X server version:                       1.10.1
Linux kernel version:                   2.6.38
Direct rendering:                       yes
Requires strict binding:                no
GLSL shaders:                           yes
Texture NPOT support:                   yes

VogonZarniwoop wrote:The kwinrc is a bit long to post here and I'm not sure how to use pastebin, but here's the kwin --replace output:

There is a plasmoid called pastebin. You can just mark text and drag and drop it on the plasmoid. Or you copy your text, right click on the plasmoid and select paste. In either case an url to your pastebin entry is put into your clipboard.

Please also add a line like this

HmpfCBR wrote:KDE 4.7.00, Kubuntu 11.04, Qt-Graphics System: Raster

Look at "Systemsettings -> Qt-Graphics System" for the latter.

Interesting already that apart from the vendor string the kwin output is identical.

Changing to Raster made it run a little bit faster, especially when I compare with many windows open. But it is still far from the smoothness I get in Gnome (unfortunately).

Here is my output from kwin --replace:
http://paste.opensuse.org/48060009

And here is my kwinrc:
http://paste.opensuse.org/52513108

(The "MaxFPS=120" and "RefreshRate=120" is there because someone got better performance with those settings, but it didn't make any difference for me).