[PLASMA 5] Specific application windows are very slow

[Laurens]

Since Plasma 5, specific windows open/draw/operate/close very slowly on my Thinkpad T60 with integrated Intel graphics (945GM):

* Settings > Workspace Theme
* Settings > Icons
* Configure Desktop > Wallpaper
* Discover

Any action with these windows consumes 100% of one cpu core and renders my laptop unusable for about half a minute.

I have had this problem throughout several Kubuntu installations on the same laptop. Other applications are fine. I tested on another computer (HP) and it didn't have the problem.

What makes these specific application windows different from others? Is it a bug? Or do these applications rely on hardware that the T60 doesn't have? Or am I missing a driver or a special setting?

[claydoh]

* Settings > Workspace Theme >>>>> Lots of thumbnails to load
* Settings > Icons >>>>> Lots of thumbnails to load
* Configure Desktop > Wallpaper >>>>> Lots of thumbnails to load
* Discover >>>>> The UI is known to be a bit slow, among other things regarding the loading of the UI

But the real problem is likely a lack of ram (unspecified) and a dual core cpu dating from 2006 to 2009, and an equally old, if not older GPU. It sounds a little like it may be using swap, which does also cause a cpu spike as the processor does have to manage this as well as its normal tasks.

I am going to guess the HP is a bit newer, has more ram, and/or more cores?

Plasma is light on the ram usage, but it does rely heavily on the GPU and cpu for things


If find you are using swap in these situations, you may want to look at this, which can reduce some systems tendency to go to swap a bit aggressively than others:
https://help.ubuntu.com/community/Sw...I_change_it.3F

[Laurens]

Thank you for the useful info. My Thinkpad has 3 GB of ram, and I never encounter ram shortages or swappiness issues. In fact, the HP, a 6720s, is just as old, also with dual core CPU, and has less ram (only 2 GB), and overall performance is much worse than the Thinkpad. But it seems to have a slightly newer GPU.

So I guess the problem might be in the Thinkpad's outdated GPU. Could it be in the fact that it supports OpenGL only up to version 1.4?

Is there a setting that can make these windows friendlier to my GPU? (Compositing is already turned off.)

[claydoh]

I am not aware of anything. My so far brief research is not turning up anything.

[Laurens]

Thank you for the research anyway :-)