I have just installed and openbox and am now running a kde/openbox session. It still isn't perfect and xorg is taking up large amounts of memory but everything is much snappier than with kwin. Memory usage on start up with system monitor running has fallen from 183Mb to 137 (still ridiculously high).

I was having problems before which were something to do with drivers/xorg/kde and my graphics card (ATI 9800 pro) and openbox makes it much more usable.

I am still tempted to restore my ubuntu 9.04 install when I get time despite not really liking gnome. kde4 still has that half finished feel.

bailout wrote:I have just installed and openbox and am now running a kde/openbox session. It still isn't perfect and xorg is taking up large amounts of memory but everything is much snappier than with kwin. Memory usage on start up with system monitor running has fallen from 183Mb to 137 (still ridiculously high).

I was having problems before which were something to do with drivers/xorg/kde and my graphics card (ATI 9800 pro) and openbox makes it much more usable.

I am still tempted to restore my ubuntu 9.04 install when I get time despite not really liking gnome. kde4 still has that half finished feel.

Is KDE + Effects slow on other distros as well? Or you could try KDE + Compiz and see if it's still slow. It might help to narrow down the problem.

To my surprise, KDE SC 4.3 is very speedy on my Toshiba nb205 netbook. It is more snappy than GNOME was on the same machine.

Kmetamorphosis wrote:To my surprise, KDE SC 4.3 is very speedy on my Toshiba nb205 netbook. It is more snappy than GNOME was on the same machine.

I see that you're using the KDE SC terminology.
Same here, I have a very old Toshiba and KDE4 works better with it than GNOME. I'm glad that KDE had such a nice revamp of code. With each release it gets better and better

Toshiba Portege S100 here - not very impressive (single core 1.6GHz processor, 1.5GB RAM) and it's working incredibly well. nVidia have really improved their graphics card drivers as of late, and it shows.

I even dazzled a Mac user with how fast it is on this rather modest machine

The thing is, if you're having slow-downs and problems, you should probably post it somewhere on bugs.kde.org along with ALL your hardware spec.

I use an ATI card with the 9.11 version of the driver. KWin is appreciably fast for me. Switching to Compiz doesn't seem to make any difference on my box.

Ok! I fully resolved my speed problems:
And here is my solution:

Go to System Settings > Desktop
In the Desktop Effects Section (On the left)
Click on the Advanced Tab
Compositing type: OpenGL
OpenGL mode: Shared Memory
Texture filter: Nearest (fastest)

The last (Texture filter) was the option that affects more in usability of the system.
I know that this solution may not work with ALL cpu/drivers/gpu but worked like a charm with my intel-based system.
Hope it will work well for many other than me.

Kubuntu karmic koala (9.10)
CPU: Intel(R) Core(TM)2 CPU T5200 @ 1.60GHz
GPU: Intel Corporation Mobile 945GM/GMS, 943/940GML Express Integrated Graphics Controller (rev 03)

Nothing helped!

Most KDE4 applications has very slow perfomance in text rendering.
For example: I open "Konsole" and "GNOME Terminal", set the same font and size, fill the scrollback with some text and try to scroll. Konsole is so slow, then I wait a second and more to see next page. At the same time in GNOME Terminal the text is flying!

Similar behavior in KMail, Dolphin.

What I have:
CPU: Intel(R) Core(TM) i5 CPU 750 @ 2.67GHz
RAM: 4GB
VIDEO: nVidia GeForce 210 ( driver nvidia 190.53 )
OS: Linux 2.6.31.5-0.1-default x86_64 (openSUSE 11.2)
KDE: 4.3.5 (KDE 4.3.5) "release 3"


xorg.conf:

Code: Select all

Section "Device"
    Identifier     "Device0"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BoardName      "GeForce 210"
    BusID          "PCI:2:0:0"
    Screen          0
EndSection
Section "Screen"
    Identifier     "Screen0"
    Device         "Device0"
    Monitor        "Monitor0"
    DefaultDepth    24
    Option         "TwinView" "0"
    Option         "metamodes" "DFP: nvidia-auto-select +0+0"
#    Option         "PixmapCacheSize" "1000000"
#    Option         "AllowSHMPixmaps" "0"
    Option         "DPI" "96 x 96"

#    Option         "RenderAccel" "true"
#    Option         "UseEvents" "false"
#    Option         "TripleBuffer" "1"
#    Option         "DamageEvents" "1"
#    Option         "BackingStore" "1"
#    Option         "PixmapCacheSize" "70000"
#    Option         "OnDemandVBlankInterrupts" "true"
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection


All commented lines - is a result from other forums about slow nvidia drivers in KDE4. Nothing helped.
Compize and other compositing is turned off.

Problem solved only if turning on a font antialising, but I hate this What's I needs to do?

When I do my test with scrolling a Konsole, then CPU load is 100% by Xorg process.

If two applications at the same time and the same preferences has different perfomance - then this is not a problem of video driver - this is a problem of that application.

It is not the applications fault. The difference between them is that they both use different underlying methods from X and for some reason methods used by Qt applications are significantly slower on your system.

On my system there is no noticable lag, at least not to the degree you are describing. I would describe mine as virtually instantaneous.

Since X is using 100% of the CPU when you do not have Anti-Aliased fonts enabled with Konsole, this is likely due to the NVidia driver not accelerating the non Anti-Aliased font drawing methods meaning it has to be done in software, which is extremely slow.

Please ensure you are using the latest compatible release of the NVidia driver from their site.

bcooksley wrote:Since X is using 100% of the CPU when you do not have Anti-Aliased fonts enabled with Konsole, this is likely due to the NVidia driver not accelerating the non Anti-Aliased font drawing methods meaning it has to be done in software, which is extremely slow.

iirc I saw this issue mentioned in an nvidia changelog

It seems that all of the people having problems with KDE4 slowness have Kubuntu in common as their Linux distribution. Being, on Gentoo Linux, I have no problems with KDE4 slowness.

I am right now on KDE 4.3.5 and I am in the process of upgrading to KDE 4.4.0 and everything is relatively fast (despite compiling KDE 4 in parallel in over 100 threads). At its peak (while I was away from my computer), my system load average exceeded 44.0, yet everything remained stable and relatively lag free. There was a tiny bit of lag when the system loads were at 44.0, but it did not last more than half a second, so I did not consider it to be a problem.

Perhaps some of this speed I am experiencing on Gentoo could be attributed to the fact that I installed Gentoo's kde-base/kdebase-meta package on my system. It is a barebones version of KDE that strips out a great deal of programs that are unnecessary to have a working desktop. I then picked and chose the components of KDE that I wanted to have, which Gentoo puts into separate meta packages. One example being kde-base/kdenetwork-meta. However, since only Kubuntu users are having these slowness issues and those on other distributions are not, I am inclined to blame Kubuntu more than I am inclined to credit Gentoo for this.

Shining Arcanine wrote:It seems that all of the people having problems with KDE4 slowness have Kubuntu in common as their Linux distribution. Being, on Gentoo Linux, I have no problems with KDE4 slowness.

Nope and most likely people with slower computers would dream of installing gentoo

aapgorilla wrote:

Shining Arcanine wrote:It seems that all of the people having problems with KDE4 slowness have Kubuntu in common as their Linux distribution. Being, on Gentoo Linux, I have no problems with KDE4 slowness.

Nope and most likely people with slower computers would dream of installing gentoo

Gentoo Linux has been installed on Netbooks according to users at the Gentoo forums. Gentoo has features that allow for faster compilations of software:

http://www.gentoo.org/doc/en/handbook/h ... t=2&chap=3

The four that come to mind are mounting /var/tmp/portage on a tmpfs, installing ccache, installing distcc on a cluster and using MAKEOPTS="-j(n+1)" where n is the number of cores.

There is also the option of compiling the binary packages for your computer on another machine and then installing the binaries.