I'm using Ubuntu 12.04 on a Lenovo X220 notebook with onboard Intel graphics.
I purchased a so called external PCIe GPU (GeForce GTX 560 Ti) which is connected via the card slot of my laptop.
Now I want to switch to the Nvidia driver on boot when the eGPU is connected. If it is not, I want to switch back to the intel driver.
I've written a little script doing the job: It places the nvidia xorg.conf on startup (on egpu) or removes it (on intel).
The problem is that the nvidia driver changes some libraries (and maybe more) so I can't use the intel driver. The following error message occurs in xorg.log:
(EE) Failed to initialize GLX extension (Compatible NVIDIA X driver not found)
My question is: Does anybody know how to switch back to the intel driver without completely removing the nvidia driver? Do I have to change some symlinks or something like this?