That’ll be for another day
Caf, your picture of the artifacts and description of how they appear is exactly the same as what we’ve been experiencing here. This is on a Samsung laptop with an AMD Radeon 750G graphics card running the proprietary driver. I’ve tried disabling the desktop effects but the issue remained.
I’ve seen this before on KDE years ago, on Pardus Linux.
You could try switching “Compositing type” between “OpenGL” and “XRender” and “Qt Graphics System” between “Native” and “Raster” (on the “Advanced” tab in the desktop effects settings)
Recommended settings would be “OpenGL” and “Raster”, but be sure to try all four combinations.
Not sure if that would help though. (But I would think especially the latter could cause such artifacts)
I’ll look in to this
The opengl option will crash plasma better to choose raster.
and I think that feature is best suited for the nvidia graphic card, correct me if I’m wrong.
Sorry, but this is getting confusing even for me.
My setting was OpenGL + Native
From what I read (if you hover on the Qt graphics system button)
OpenGL + Raster is the preferred
Hi caf,
I am referring to the qt graphicssystem opengl if you choose the opengl in it, it crashes
plasma as soon as you login but you can use it in a per application basis in your kde apps.
Sorry about the confusion.
OpenGL is the default setting as opposed to XRender
I never had trouble with the default or plasma crashes.
Any chance this is a power issue ? ie the power to drive the graphics card is marginal and the power supply has aged and now is borderline wrt the power being provided to the graphic card.
This is a VERY speculative suggestion, but IMHO something you could consider (and reject if considered not the case).
Would seem unlikely as my GPU collects it’s power from the board only
In the desktop effect settings I spoke about you can’t set the Qt graphicssystem to OpenGL. Qt’s OpenGL backend is still experimental.
Also this settings only effect kwin and not other applications. Maybe you’re talking about “kcm-qt-graphicssystem”, available in KDE:Extra, where you can set the graphicssystem for all Qt apps?
According to Desktop Effects Performance - KDE UserBase Wiki, the only recommended combinations are:
- OpenGL with raster
- XRender with native
- No Compositing:
[LIST] - native in case of remote connections (recommended window decoration: Laptop)
- raster if using fancy window decoration (including Oxygen and Plastik in 4.10 or later)
[/LIST]
But that recommendation is more based on speed I think.
And as I said, I have no idea if these settings could cause the described glitches. But I remember to see graphical glitches in individual applications depending on Qt’s graphicssystem setting. (e.g. kpovmodeler just shows garbage with “native”, while konqueror/KHTML renders some pages incorrectly with “raster”… Well, I just tried kpovmodeler again, now it just crashes with “native” ;))
FYI: I 99% of the time run with no desktop effects on all my machines
If that matters?
Your video card is failing. Replace and see if it goes away.
Usually you will find ruptured capacitors when this kind of thing
starts. Eventually you will have random machine hangs or it may nbot boot at
all.
I found bloated capacitors too when my motherboard failed
> GofBorg;2554747 Wrote:
>> Usually you will find ruptured capacitors when this kind of thing
> I found bloated capacitors too when my motherboard failed
Common problem…and an even more interesting story beginning back in 2003.
http://spectrum.ieee.org/computing/hardware/leaking-capacitors-muck-up-
motherboards
I had a motherboard go 2004/5, and remembering well seeing a few distorted capacitors.
> I had a motherboard go 2004/5, and remembering well seeing a few
> distorted capacitors.
>
Still happening. I have a PCIe video card on the shelf next to me with
8 blown caps on it. No telling how many billions of bad caps are still out
there.
Despite a recent driver update from the Ioda repo, and a bit of tweaking in vain, I’m still experiencing this problem. 
As Caf reports, I too can log out and back in again, and it’s gone, but on most cold boots its there. I’ve never seen it before when Ubuntu was installed, and the Windows 7 install we also have on this laptop is fine, so I don’t think it’s hardware related. It’s not a very old machine anyway, so it better not be!
>
Ah. I didn’t catch that it was on a laptop. All bets are off then.
Laptops are just weird because you never really know what is inside them.
The same vendor can produce the same laptop over 6 months and
go through three or more revs of hardware in that same time period. At risk
of moving into support at this point so all I’ll say is disable all effects
or boot into a simpler DE like xfce and see if it goes away.
Hi GofBorg. It is a laptop in my instance, but I believe the OP reported the issue on a desktop PC.
I have tried disabling effects but I still got the problem. I think it’s possibly something KDE related, but I wouldn’t have the knowledge to discern for sure I’m afraid.
I might install another DE and see if that works though. 