Why does my CPU usage keep spiking?

My CPU usage keeps spiking a lot. I can be sitting on my desktop and my CPU usage will go up to around 90%, according to Conky. Here is the output of top:

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND 
 3183 thomas    25   5  868m  66m  19m S   12  1.7   1:14.99 chromium-browse    
 1151 root      20   0  149m  45m  19m S   11  1.1   8:07.03 Xorg               
 5739 thomas    20   0  190m  19m  12m R    6  0.5   0:00.19 nvidia-settings    
 1891 thomas    20   0  134m  34m 4436 S    4  0.9   1:35.87 beam.smp           
 4840 thomas    20   0  433m  18m  12m S    3  0.5   0:01.13 gnome-terminal     
   23 root      20   0     0    0    0 S    1  0.0   0:46.66 kacpid         

And right now my CPU usage is around 70%. It's as if there is some malicious process or something hidden away just eating up my CPU usage.

If it helps to know, I'm running a Core 2 Duo with the nvidia drivers installed, version 260.19.06.

Solution 1:

This CPU usage spike usually tends to come from programs that need to run periodically (like gwibber-service) to update something in the background. You should find any applications that are doing this (using system monitor/top it's easy to catch the culprit in action).

BTW it happens to me as well, and I was able to determine a few culprits: docky, my music player (banshee and rhythmbox are both rather bad behaved at times, but probably because of too many plugins), gwibber, and apt (looking for updates in the background). These may not be the cause of your problems, but you can try seeing if any are responsible.