Are the nvidia drivers not performing as they should?

Question

I have a dream... And in that dream I am running full HD videos in XBMC on my Sapphire EDGE HD2 media pc. It is based on the ION 2 chip. I installed Ubuntu on it and in Ubuntu I installed XBMC. I chose the “recomended” driver in the additional drivers window of ubuntu.

After this I played around with XBMC testing it out. Immediately I found the performance unsatisfactory. Playing 720p and 1080p video files caused horizontal “lagging stripes”, for lack of a better word, in the picture.

Now I started reading up on installing the newest drivers form Nvidia. I found this explanation: http://www.ubuntugeek.com

Substituting gdm with lightdm it worked like a charm. After activating the new drivers i found a pleasing performance boost to the video rendering. Gone was all the horizontal “lagging stripes” and the first few films I saw was very pretty.

However. A few of the highest resolution films still seemed to be problematic. In scenes of the movies where most of the image consisted of moving objects there where serious issues. Its not “stripes” or “lag” but simply a drop in frame-rate. (Just like playing a game with too low FPS)

So, I started reading more on Nvidia drivers for linux and found some mention that the above method of installing the Nvidia drivers was not “recomended”. So I purged and removed all things Nvidia from my system and ran this:

sudo apt-add-repository ppa:ubuntu-x-swat/x-updates
sudo apt-get update
sudo apt-get install nvidia-current 

I belive I also tried some other repositories as well. I even did a clean install of ubuntu trying each method with a “fresh” start. Still the same FPS problem.

Now, at this point I am thinking it is a hardware issue. Maybe the the hardware in this little device just cant handle the films with the best quality.

But here is the kicker: I installed dualboot Windows 7 and loaded it up just to see what happened. Using the exact same video file in Windows on Windows Mediaplayer it runs super smooth, no problem at all. So, obviously it is not a hardware performance issue.

I'd hate to have to use Windows instead of Ubuntu to run on my media-PC. Anyone want to help, suggestions?

System Info:

Ubuntu 11.10

XBMC Dharma 10.0

NVIDIA-Linux-x86-285.05.09

Sapphire EDGE HD2 mini PC. (Specs)

Answer 1

Also, adding this to your /etc/X11/xorg.conf file might help:

Section "Extensions"
  Option "Composite" "Disable"
EndSection

If you don't have a xorg.conf, run this to create it for you:

sudo nvidia-xconfig

This method completely solved my problems with the horizontal lag in xbmc!

Answer 2

It looks like your XMBC isn't using VDPAU.

Your CPU is too slow to decode HD videos, it needs special-purpose hardware from your GPU (NVidia ION 2) in order to play HD videos. VDPAU is the software component that manages this for Linux with NVidia hardware.

In your XBMC, in Settings -> Videos -> Player make sure VDPAU is selected as the Render method.