How to disable discrete GPU using NVIDIA drivers?

I have a DELL studio XPS 13 (aka 1340) as of 12.04 most things run smoothly out of the box, but I have some power draining and warmness issues (if not to be called terrible heat issues)

The system came with a NVIDIA GeForce 9500M (which has Hybrid SLI) and it shows up in "lspci" as these 2 cards

02:00.0 VGA compatible controller: NVIDIA Corporation G98 [GeForce 9200M GS] (rev a1)
03:00.0 VGA compatible controller: NVIDIA Corporation C79 [GeForce 9400M G] (rev b1)

I had to install nvidia-current over noveau driver 'cause noveau does freeze the system after suspension. By installing nvidia-current and running nvidia-xconfig the resume process after suspension is fixed.

By the way both with nvidia-current and noveau the system drains a lot of battery and heats up a lot. I suppose this is because the discrete GPU is always on. I don't really need 3D graphics on this system, if not the minimal to run unity and compiz for window management.

So my question is: How do I disable, using nvidia-current, the discrete GPU 9200M and use only the integrated one 9400M?

notes:

• In BIOS I have no option to disable discrete GPU
• This I think is not applicable because of the suspension-freeze issue (with noveau): https://help.ubuntu.com/community/HybridGraphics
• I've found this but I don't know which --sli option I should choose to fit my needs:
  http://manpages.ubuntu.com/manpages/hardy/man1/nvidia-xconfig.1.html
• My system has not optimus or cuda, but anyone can tell me if
  bumblebee can work for me?

Solution 1:

I have the same laptop as you. I've tried bumblebee, and it did not work for me. You can read about my experiences in this thread: https://lists.launchpad.net/hybrid-graphics-linux/msg02295.html

I am actually trying to use my discrete 9200M GS GPU, and I am continuing to post messages there to ask questions and report my progress. The issue at the moment seems to be that the NVIDIA kernel driver never wants to connect the LCD display to the dedicated card, so I'm trying to figure out how to tell it to do that.

If you're only interested in disabling yours, however, the only solution I've found is a kernel module, which simply calls the ACPI method to disable the dedicated GPU: http://luizfar.wordpress.com/2010/06/29/how-to-switch-off-xps1340-discrete-video-card-on-linux/

Bumblebee is supposed to be able to do this more elegantly, even for legacy systems like ours, but when I try to run it, it complains that I don't have an Optimus system (obviously).

Hope this was helpful, and do send a message to that list if you make any progress using the discrete GPU.