Ask Ubuntu is a question and answer site for Ubuntu users and developers. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have a MacbookPro 5,1/5,2/5,3 that comes with two graphic cards, and by default I get the 9600M GT that consumes more battery that the other one. I have no idea how to deactivate it and activate the second one.

More details after the Bruno's reply:

I'm using Ubuntu :

  • 11.10 64 bits with kernel 3.0.0-15-generic (Zegnus, MBP 5,1)
  • 12.04 64 bits with kernel 3.2-0-24-generic (Megagolgoth, MBP 5,3)

I have installed rEFIt 0.14, and GRUB2 EFI64

I've modified the entry on the file /boot/grub/grub.cfg adding

outb 0x750 0

even though at the top of the file it says:


It is automatically generated by grub-mkconfig using templates
from /etc/grub.d and settings from /etc/default/grub

I save the file, boot, select the entry and then I have a black screen and nothing more happens.

I've tried too, with the same result.

Thank you.

share|improve this question
Have you had any luck with this? I have the same problem, if I disable 9600 with outb, I get black screen. – Mladen Jablanović Jan 4 '14 at 20:22
@MladenJablanović: I'm on MBP5,3 and having severe trouble with the graphics. Maybe we should share results. – Max Ried Mar 25 '14 at 12:33
This helped me:… – Mladen Jablanović Mar 25 '14 at 21:22
I need more help. After adding Outb 0x750 0 to grub.cfg. I stuck at black screen at startup. I even cant switch between terminals using alt+F1. What do you suggest My laptop is 5,1 9600M GT with 256 megs of memory. – user264542 Apr 2 '14 at 11:35

To disable the Nvidia 9600M GT you have to add the following to the grub menu entry outb 750x0, ie:

menuentry 'Ubuntu, with Linux 3.0.0-12-generic' --class ubuntu --class gnu-linux     --class gnu --class os {
    outb 0x750 0
    set gfxpayload=$linux_gfx_mode
    insmod gzio
    insmod part_gpt
    insmod ext2
    set root='(hd0,gpt5)'
    search --no-floppy --fs-uuid --set=root bc495raf-515r-4r2b-b3de-0ec679a7303a
    linux   /boot/vmlinuz-3.0.0-12-generic root=UUID=bc495raf-515r-4r2b-    b3de-0ec679a7303a ro hpet=force
    initrd  /boot/initrd.img-3.0.0-12-generic

Additionally for powerdown after resume after suspend:

On resume, the discrete graphics controller will be turned on and active. We need to turn it off and switch back to the integrated GPU.

This can be done with a very simple little program:

#include <stdio.h>
#include <sys/io.h>

#define PORT_SWITCH_SELECT 0x728
#define PORT_SWITCH_DDC 0x740

static int gmux_switch_to_igd()
return 0;

    static void mbp_gpu_power(int state)
    outb(state, PORT_DISCRETE_POWER);

int main(int argc, char **argv)
if (iopl(3) < 0) {
perror ("No IO permissions");
return 1;
return 0;

Save that in a file called igd.c. Compile it with gcc -O2 igd.c -o igd. This will create an executable called igd. Executed with superuser privileges, it will turn off the discrete controller and switch to the integrated controller.

Now we need to execute this on resume. Create a file called /etc/pm/sleep.d/10igd

It should contain:


Where /path/to is the path to where you put the igd executable we created in the previous step.

chmod +x /etc/pm/sleep.d/10igd

This file will be executed on suspend and resume. Done right, that 10igd script would check to see if this is a suspend/resume/freeze/thaw and only execute when needed. As-is, it executes on all of them. No big deal, it won't hurt to run it during freeze or suspend.

I got everything working on my mbp5,1: Sound, LCD Backlight, Keyboard backlight, Fans running low (since disabling 9600M GT),Apple like short cut (CMD+C to copy),Flash (almost stable)... So just ask if you need more help

share|improve this answer
Hi @BrunoPereira, I've updated my question with more details based on your reply. Thank you very much. – zegnus Feb 8 '12 at 13:03

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.