Our latest look at the current development state of Ubuntu 13.10 is comparing the "Saucy Salamander" performance against that of Ubuntu 13.04, 12.10, 12.04.2 LTS, and 11.10. Testing was done with an Intel Sandy Bridge system to see how the Ubuntu Linux performance has evolved over the past two years in the road to the October release of Ubuntu 13.10.
From this report, graphic processing of frames per second has improves from 12.10. In 13.10, frames-per-second dropped a little. Was the Radeon 4650 using it's open source drivers or the mesa drivers?