No I don't think it is the HDD.
Originally Posted by Zirts
I think we can use your screenshots to understand what is happening. And I hope some other guys might add ideas too
But now to the iotop and top tests.
So I watched a video and at the same time I had two terminals open one with top and one with iotop -o -d7
iotop showed me that gnome-shell was disk reading with 100 KB/s if i remember correctly now ( was the biggest one there) when the stutter occurred and Xorg took 60% cpu usage. I will wait up one more stutter and take a screenshot this time which I should have done long ago.
Edit: uploaded pictures. iotop did not update at the exact same time when Xorg went up but the picture after shows it's aftermath.
As far as I can see, xorg is not causing any swapping, and it should not be responsible for reading from the video file. I think that it cannot quite keep the pace necessary to show the video smoothly.
I cannot see any information about the version and flavour of Ubuntu except [ubuntu] in the title.
- Is it 12.04 LTS or 12.10?
- What desktop environment is it? Unity or some other flavour of gnome 3 shell? Are you running compiz?
I suggest that you try
- either to download iso files of Lubuntu and Xubuntu and try them live (testing with VLC (temporary install into the live session). Maybe this is more complicated, but it does not mess with your installed system
- or install the corresponding desktop environments into your present Ubuntu. This is easy to do, and should not destroy anything, but your menus might become a bit cluttered.
And you can select desktop environment at the log in screen.
sudo apt-get install lubuntu-desktop
sudo apt-get install xubuntu-desktop
My experience is that Lubuntu plays video much better than [vanilla] Ubuntu, because the its desktop environment LXDE is ultra light-weight.
You get extreme speed if you have no desktop environment at all, only the openbox window manager, that you can also select at the log in screen (if you have Lubuntu or lubuntu-desktop). Right-click on the background to get a terminal window and go ahead ...
I guess you think that you should get both eye-candy and speed, but maybe you can select different desktop environments depending on the task.