Hi, i would just like ti share some of my thoughts about KDE4 interface laggy performance.

The thing is, i tried every single KDE4 release to date on multiple platforms (Debian, Kubuntu, Arch, OpenSUSE and PCBSD), and multiple pc's (all modern configurations), but always got the same result - slow responsiveness!
Since i tried it on all those platforms, i can easily eliminate my pc's hardware or distributions as a source of the problem.

For example, when i open root dolphin, or root konsole there's always that pop-up that asks for root password - EVERY SINGLE TIME that window first loads just an empty grey frame, and then for like a fraction of a second, everything else (letters, forms,...). Also, the same thing happens when opening highly populated windows like dolphin, or system control, etc.

This is also noticable when browsing the system fast, like opening and closing windows, minimizing and maximizing, opening kmenu, then fast switching to some 3rd party application like FF, TB, K3B, etc.

It just lacks FLUIDITY!

I don't want to start a flame, but take Win7 or OSX for example - those environments doesn't get on the way of doing regular everyday tasks. I really don't want to notice the environments speed everytime i'm doing sth on my machine...

Don't get me wrong, i like KDE4 and that's the main reason for writing this, but please fix the speed. It's just ruining all those great things in KDE4.

Thank you.

here is with an intel 945gm and 1 gb of ram it runs as fast as light.

i could say kde is faster than gnome.

Perhaps you have not found the right combination? I know I went through a lot of different distros before landing on Fedora 12. Some were in 32 bit and others with 64 bit, but, all on the same machine, (see signature.) It is a matter of hardware versus drivers versus kernels and it goes on and on. You cannot just blame KDE, they don't make the kernel, just the desktop. It could be your cores, (Mint, kubuntu, ubuntu, Fedora) are all cores, slowing you down. Keep trying, you'll find something that works.

this basically is because a complete new kde session is loaded for the root user

another problem is the amount of debug info spat into the terminal: open kdebugdialog and deselect everything (do this as root and as a regular user)

pericaa wrote:Hi, i would just like ti share some of my thoughts about KDE4 interface laggy performance.

That's all video driver speed you're experiencing (kde has a lot less to do with it).

What video card/driver are you using?

@ bobcollard: Tried Fedora. Performance still sucks. I really don't think kernel has anything to do with it, since PCBSD acts the same and it's a whole different core...

@ rdieter: It's the same on various PC's, but my 2 main configurations are based on ATI: HD2600XT and HD3470. Others are ati integrated, intel integrated and nvidia 8400 (i think), all default drivers.

HD2600XT and HD3470 were both thoroughly tested with FGLRX and radeonhd (various versions through a long period of time). Also, the desktop composition was both on and off. The thing is, KDE3 is just great on the same configurations - it works without a problem, and has that fantastic fluidity when browsing the system. KDE4 doesn't have it.

pericaa wrote:HD2600XT and HD3470 were both thoroughly tested with FGLRX and radeonhd (various versions through a long period of time). Also, the desktop composition was both on and off. The thing is, KDE3 is just great on the same configurations - it works without a problem, and has that fantastic fluidity when browsing the system. KDE4 doesn't have it.

I am using a HD4570 with the 9.11 version of the driver (using the driver for the 4550 series). WM performance for me is appreciably smooth and I don't experience any form of lag. It's as good as Win7, with which I dual boot.

So I agree with rdieter -- KDE hasn't got much to do with choppy graphics.

I find that my system ( Intel GM965 with Desktop Effects enabled ) doesn't have any of the problems you describe either, except when KDE hits disk, due to needing files or swapping. KDE 4.4, compiled from Trunk.

bcooksley wrote:I find that my system ( Intel GM965 with Desktop Effects enabled ) doesn't have any of the problems you describe either, except when KDE hits disk, due to needing files or swapping. KDE 4.4, compiled from Trunk.

I guess you are lucky, I also see an empty grey (or cyanish green for some stuff that uses argb visual) frame when apps first load. I opened several bug reports about those but they were closed as duplicates

eg like [Bug 215242], [Bug 218773] or [Bug 218781] but I have more...

It might even be that kde 4 might not be slow in benchmarks but bugs like above really give a feeling of slowness. Atm I am trying to create an inventory of all the things in kde which give me an impression of sluggishness but might actually not be sluggish...

@aapgorilla: The Intel drivers as shipped in SUSE 11.0 and 11.1 were like that. Utterly hopeless. This has been completed cured with 11.2 fortunately. I usually only see a blank window when my system is under load ( swapping )

this was with nvidia and ati

i'm sick of everyone blaming all the other parts of linux when questioned theirs. now it's video drivers, kernel etc etc

here is a simple experiment i've done

1. installed opensuse 11.0 with kde 4.0
feels fast. slower than kde 3.5 on opensuse 10.3 but hey - everyone promised that with incresing qt 4.x and kde 4.x the performance will increase.

2. updated qt to 4.6 (this is on kde 4.0)
no difference in perfromance. kde 4.0 feels fast

3. updated kde to 4.4
and here we are. everything is slow as HELL!


i don't have a new shiny computer so these performance issues are really noticable.

You may feel "sick" about blaming things, but Plasma and other KDE technologies have exposed problems in drivers that no one bothered to fix before, because no one was using them that way.

In addition, 4.4 has not been officially released yet, so is likely not compiled in Release mode, which means it will not be as optimised, thus running slower and consuming more memory.

4.3 performance is the same as 4.4 here.