System slow performance and lagging

[Juhele]

Hi,
some time ago I upgraded my laptop to 15.04 with new Plasma (updated last Friday). I experienced various problems (like black screen after login etc) which forced my to almost delete configs from my current account and set the KDE desktop from scratch again.
However the performance of the system is poor - although I switched off most effects and also the Plasma search, my current situation looks this way:



Computer is:

Processor		: 4x Intel(R) Core(TM) i3 CPU       M 350  @ 2.27GHz
Memory		: 2960MB (1636MB used)
Operating System		: Ubuntu 15.04
-Display-
Resolution		: 1366x768 pixels
OpenGL Renderer		: Unknown
X11 Vendor		: The X.Org Foundation
-Multimedia-
Audio Adapter		: HDA-Intel - HDA Intel MID

The CPU load was more than 40% even when doing nothing. Switched off Akonadi using "akonadictl stop" (any suggestion how to make it stopped permanently?) and is little bit better but there are still lags during common work - like clicking on something in bottom panel always has some short delay etc. Do not have this problem on other machine with KDE 4.14.

any ideas?

thanks

[claydoh]

Aside from firefox using 48% cpu , it's gobbling up most all your ram (3 x 23.1%= 69%!?!) , which is slowing down your system by utilising swap.
Sometimes, on some systems, it seems that it goes to use swap too early, or more aggressively. My old core2duo laptop does this, but not my less-old core 2 PC, both with 4gb ram, and is not specific to 15.04. From your screenshot, Firefox is using a LOT of ram and cpu, but other things might be as well , such as the file indexer until it is done doing its initial run. Akonadi is less likely a culprit these days.


http://askubuntu.com/questions/15779...ty-of-free-ram

The top answer provides a setting to edit that will reduce this problem greatly, and other responses provide some explanation for why it happens.

setting swappiness to 10 is a good recommendation.

[TWPonKubuntu]

Swappiness with 14.04 LTS

Claydoh, thanks for the advisory.

I'm running 14.04 LTS and have noticed a general system slowdown (lagging) with high CPU usage in the last 10 days.

I applied the change to vm.swappiness=10 in ./etc/sysctl.conf
I did have to create the parameter in that file.

I immediately see a perceptible increase in speed for Firefox startup.

I'll watch system and app startup speeds and CPU usage for the next few days and report any changes. Since I have no data on speeds prior to this change, it will be a subjective test.

[claydoh]

As it is swap, hard disk usage is what is slowing things down, as drive space is being used to help with ram. This is what one needs to look at since it is not necessarily any one program causing it.

[jlittle]

I see what looks like a flashplugin-installer process running. That should only run once when applying a new flash update, maybe once or twice a month. Maybe it is trying to run repeatedly, interacting negatively with firefox. I suggest exiting firefox and see if it is still there; if so, kill it and try to run it in a terminal. I'm not sure the best way to do that, maybe sudo apt-get install --reinstall flashplugin-installer.

[Juhele]

Thanks,
setting swappiness to 10 really helped for me. It cannot change the power-hungry Firefox of course but now ksysguard shows me swap=0 and system behaves the way I was used - so no lags when switching between windows etc.