OS: debian 8.0 jessie
KDE: 4.14.2
Network Manager: 0.9.10.0
Cause on my computer: Network Manager

Yesterday morning, I turned on my computer screen, had a look at some opened
windows and terminals, as I thought kde's window preview is very good, I wanted
to have a play with it, but I found the response was very slow! So I checked
the output of the top command, and I saw plasma-desktop was using 100% cpu of
one core, that time I didn't know its effection, but I thought it caused my
system slow.

So I searched in google, I just input several words "plasma desktop high ",
and google gave me some hints, so I searched "plasma desktop high cpu usage",
there are so many pages about this issue, I didn't find a nice answer for me,
but found that this problem had been existed for a very long time, seemed
first post about this was in 2009. But I need to use my computer,so I just
restart the application plasma-desktop simply.

At first everything was fine and the system run smoothly, after 4-6 hours,
plasma-desktop and xorg occupied 20% cpu each one steadily.
Someone said it's 64 bits vmware's problem, but at last I found it's the
problem of the Network Manager! After I closed system tray at the bottom, the
cpu usage of xorg and plasma-desktop both went down to normal level, from my
feeling.

In fact I closed almost everything near the system tray, including system
tray, digital clock, kmix(volume controller), activity and I stopped my
virtual machine in vmware(so the vmware icon disappeared), only start menu
and the input method left, after that the cpu usage of xorg and
plasma-desktop went down. And then I added them one by one to find which one
caused the disgusting problem, at last I found it's the Network Manager. I
think it's the network speed statistic caused the problem, from my viewpoint
that feature/function is useless, no offence, it's the job of system monitor.

I think I will install another Network Manager easy to use. Do one thing and
do it well.

My system is debian 8.0 jessie, kde's version is 4.14.2, and the version of
the network manager is 0.9.10.0.
Hoping this will help buddies had the same situation.

Have you read this thread, esp. Jan's reply? viewtopic.php?f=289&t=121533&start=15#p330924

Heiko Tietze wrote:Have you read this thread, esp. Jan's reply? viewtopic.php?f=289&t=121533&start=15#p330924

Yes, thank you, I saw that before when I opened lots of webpages to read, and I closed those pages, later I want to add that url to my post, but I just can't found that page, as it's just a line of a post, difficult to find. And I didn't that believe it that time as nobody comfirmed it.

I posted a new one just want to make it easy to find and more trustworthy. Thank you for finding that url and posting it here again.