I have the Nvidia GeForce 650M (built into a Lenovo Y400) and was having various problems and had difficulty finding clear instructions, most answers assume you have Ubuntu. I'm using BunsenLabs Debian 8 Jessie. This solved all my problems:
Edit /etc/grub.d/10_linux/
and add the line GRUB_CMDLINE_LINUX_DEFAULT="quiet splash nouveau.noaccel=1"
Then run update-grub
and reboot. This allows me to use subpixel smoothing without garbled text, YouTube without freezing up, etc.
Personal notes: I did not bother to install Nvidia drivers. I suppose if you install the right driver, and configure xserver properly, then maybe you don't need to disable acceleration? Initially, I tried nvidia-detect
and installed Nvidia drivers via apt-get, but either they didn't work or they messed up my xserver config. Rather than wander around lost in a terminal with no graphics, I uninstalled all of my Nvidia drivers. I'm able to do all of my work without the Nvidia drivers now. Longer explanation here http://pjbrunet.com/customizing-bunsenlabs-linux/