Note : This may not be the answer you're looking for, but it can be usefull.

Flash is gonna be hard on your CPU, but 80% of an i5 is ... well, a lot. I noticed before that the built-in Flash from Chrome was using more CPU than the external flash-plugin in Firefox. But 20% for looking at desktop, it seems too much.

For example, with my AMD AthlonII X4 3.0Ghz, i'm at 2-20% of each core, using full accelerated 1080p desktop, firefox running, terminal and mouse/keyboard activity. All of that, while looking at top and gnome-system-monitor, which are pretty heavy themselves.

Is it bad if my CPU is loaded ?

Not specially. I heard once that Linux, compared to other OS, was designed to use the best out of our hardware. That means it's heavier if you have a better hardware.

As storm09f87a said : "Unused CPU cycles are wasted CPU cycles". It is fundamentally true. Keep this in mind

What to do when my CPU activity seems too high ?

• You can look at your CPU activity with the command top, it's a CLI program (command-line interface).




• You can also look at it (total and details) with gnome-system-monitor, with a GUI (graphical user interface)

I, for instance, use the two combined :

You can see on this screenshot that Xorg takes a lot. But actually,
it is because of the mouse activity, not the display itself. You'll
also see that the gnome-system-monitor is heavy: but you can ignore
this, because this program isn't always running.

The point of this, it's to see which process takes your CPU cycles. Sometimes, you can notice a bug, a leak, that is caused by a process that should not use so much power.

You can try then to kill it with the command killall nameoftheprocess. If it was necessary for the OS to run, then either it will restart itself, or you'll have to reboot.

You can also seek what program/service is related to this process and reinstall, optimise, or restart it. You can fill a bug report if needed.

You can, if you wish, use a tool designed to make Linux more eco-friendly on a desktop PC, and save energy on a laptop.

I never tried it on a desktop PC, but from what I've heard, it helps to reduce the temperature of your system and better regulate the hardware. That tool is TLP by Linrunner.

" TLP brings you the benefits of advanced power management for Linux without the need to understand every technical detail. TLP comes with a default configuration already optimized for battery life, so you may just install and forget it. Nevertheless TLP is highly customizable to fulfil your specific requirements."

You can install it with these command-lines :

sudo add-apt-repository -y ppa:linrunner/tlp

sudo apt-get update

sudo apt-get install tlp tlp-rdw

It will be used on next reboot. You can also manually start it with sudo tlp start. You'll find the documentation on Linrunner's website.

I am experiencing system errors...

Me too, don't worry. Ubuntu has the filthy habit to report every little error, even when it shouldn't (in my opinion) be noticed to the user.

Depending on the errors : if they are regular, where do they come from, if they keep the system to properly work, ... you can desactivate the "error" message. I always do that, because it's a real pain in the keyboard.

To desactivate the notifications on every error, use this command-line :

sudo sed -i 's/enabled=1/enabled=0/g' /etc/default/apport

(or pass enabled=1 to enable=0 in /etc/default/apport file).