I have installed Ubuntu 12.04 in a Samsung Chronos Series 7.
This machine has NVIDIA Optimus system (Nvidia 640M plus an Intel 4000HD). I have Bumblebee installed and everything works fine with optirun, HDMI output etc.
There is only one small problem: I notice waves on screen (as if the refresh rate is too low). This is more noticeable on dark colors like gray and also on transparencies (like the dash).
This is not an hardware problem. On windows everything works fine I also notice that this waves only appear when the "ubuntu" logo first shows on the screen i.e. not in grub or bios screen.
I have already reinstalled drivers, changed resolution, changed refresh rate on compiz settings, etc. This just keep happening.
Any tips on this? Thank you.