Optimizing video on ubuntu

I'd like to get better performance out of my video cards. I have nvidia and ati cards in systems. The default drivers from Ubuntu work just fine, but if I can get better video playback or GoogleEarth performance, I think I need to try using closed binary drivers.

This link looks like the most helpful documentation I've seen for this process: https://help.ubuntu.com/community/Video

Background

The current state of affairs is that my nvidia machine will run GoogleEarth and play video. The ati machine will not run GoogleEarth and it sometimes stutters on video.

rday@merkli:/var/log$ lspci | grep VGA
02:00.0 VGA compatible controller: ATI Technologies Inc R350 AH [Radeon 9800]
rday@merkli:/var/log$ lsmod | grep radeon
radeon                636000  2 
ttm                    36212  1 radeon
drm                   159584  4 radeon,ttm
i2c_algo_bit            5760  1 radeon

rday@weasel:/var/log/landscape$ lspci | grep VGA
05:00.0 VGA compatible controller: nVidia Corporation G71 [GeForce 7300 GS] (rev a1)
rday@weasel:/var/log/landscape$ lsmod | grep nvidia
nvidia              10316904  36