I have fresh install of ubuntu 12.04.4 LTS and CUDA 5.5 with nvidia-331.20 driver. There are 4 GeForce GTX 780 on board. X runs on integrated card, while Nvidia cards are superposed to do some calculations.
My laptop has both an onboard Intel graphics card and a nVidia GeForce with Cuda and Optimus. I installed Bumblebee and can now run applications on the nVidia card by typing optirun [application name] in terminal.
Here we provide the download link for the latest driver for nVidia GeForce GTX590 VGA graphic card series. This is the nVidia GeForce GTX590 officially certified driver for Windows 7 32bit version 267.85.