Xorg often taking a lot of CPU, whole system slow

[Colin Law]

2010/1/18 sam tygier <samtygier at yahoo.co.uk>:
> Dotan Cohen wrote:
>> Often, my Kubuntu 9.10 system slows to a crawl. When this happens,
>> Xorg is usually the culprit:
>>
>> top - 10:51:32 up  2:03,  2 users,  load average: 0.72, 0.49, 0.29
>> Tasks: 168 total,   2 running, 166 sleeping,   0 stopped,   0 zombie
>> Cpu(s): 31.1%us,  7.9%sy,  0.0%ni, 61.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
>> Mem:   2060628k total,  1631280k used,   429348k free,     1132k buffers
>> Swap:  2931852k total,        0k used,  2931852k free,   692632k cached
>>
>>   PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
>>  1206 root      20   0  526m 157m  19m S   45  7.8  26:22.25 Xorg
>>  1756 dotancoh  20   0  472m 240m  24m S   18 11.9  29:01.06 firefox
>>  1632 dotancoh  20   0  244m  28m  20m S    7  1.4   8:59.91 kwin
>>
>>
>> What is Xorg doing? How can I diagnose this? Thanks!
>>
>
> Xorg is the graphics system. note that Xorg only draws stuff when a program tells it to. in this case it looks like firefox is the main culprit (and maybe kwin) too. this could be because firefox has animations running (maybe not in the visible tab).
>
> i recommend installing flash block (in firefox do tools->add-ons), which will prevent flash animations starting automatically (you click on a play button to start them). also set gifs to only play once http://kb.mozillazine.org/Animated_images

Is the suggestion here that using FF and allowing flash content
routinely causes Ubuntu to slow to a crawl?  Surely not.  I have never
seen any such issue running a relatively lowly several year old PC.

Dotan, I presume you have tried switching off Visual Effects?

Colin