I have a Thinkpad W520 with Intel HD3000 onboard graphics as well as an Nvidia 1000M graphics chip, and I'm running Ubuntu 13.04. I experience a rather big difference in how smooth Unity appears with Intel vs. Nvidia.
Although games run much better with the dedicated Nvidia card, Unity seems to like the Intel graphics better. This is especially noticeable when minimizing/maximizing windows and using the exposé feature, as well as other effects. Why is this? You would suppose the better graphics card leads to better Compiz performance, but this does not seem to be the case.
I'm not really talking about Unity being slow, but instead a bit laggy, as I'm dropping frames, with Nvidia that is.
It's not a Optimus problem as I'm lucky to have a BIOS that allows me to choose whichever I prefer.
Are there any fixes or improvements that I can do to improve my Unity appearance and performance with Nvidia graphics?