T520 optimus + linux

Hi there,

I know that optimus isnt compatible with linux, but its possible to install linux smoothly
on a optimus machine? What would happen in that case?

I read that only the integrated graphics would be in use, but what about the discrete graphic card? It would be deactiveted? What about the battery, while "deactivated", the discrete will spent charge??

Thanks =)

 

You can choose between Integrated only and Discrete only in BIOS if you choose to run Linux.

 

The Colonel is correct. One clarification -it is my understanding that once you have made a choice in BIOS, you need to keep it that way if you're running Linux. You can't switch back and forth.

If you have graphics set to integrated, the nvidia gpu will be switched off, extending battery life.

 

Hi Guys:

I actually want to go that route as well. I used a Live version of Ubuntu for my desktop and really found the interface much more friendly than the Windows interface. In BIOS, the graphics of my T520 is set to Optimus.

If I install Linux, will it choose the Integrated GPU and disable the the discrete GPU? I really don't relish the thought of going in BIOS every time I switch OS. Is there no other alternative at this point?

Thanks,
Claude

 

someone can correct me if optimus is different but I have a t500 with ati and intel graphics running ubuntu 9.04

In windows i have both drivers installed but not the switchable driver. I usually set my bios to discrete and I have the ati driver installed for ubuntu. I can use both OSes in this mode and if I need to save battery I operate in windows and switch to integrated in the bios. Ubuntu gets about 1-1.5 hr worse battery for me anyway so I don't use ubuntu much unplugged.

this method is best for me because I don't need the battery life that much but do need to switch OSes regularly and am too lazy to go into bios every time.

my guess is that with the bios setting as optimus, you will use whatever driver you have installed in ubuntu, and have switchable graphics in windows.

 

This is my experience with linux and windows dual-boot and switchable gpu's (not optimus):

In linux, 2 options: one gpu or the other.
In windows (not xp), 3 options: switchable between, or one or the other.

If external gpu used in linux, rebooting into windows will go also use the external, without switchability.
If internal in used in linux, rebooting into windows will go also use the internal, without switchability.

To boot from linux into windows using either the other gpu or switchable, then a visit to the bios is called for.
To boot from windows using switchable into linux you also have visit the bios.

From windows not using switchable gpu's, rebooting into linux without visiting the bios will boot into the same gpu as in use in windows.

 

Switchable graphics is completely different from optimus (where you have no direct influence on which chip is doing the rendering).

There is the vga switcheroo hack that does switchable graphics on the fly on some models. ATI only.

Optimus is undocumented and will not work in anything but a few Windows versions.

The thinkpad bios has a "OS detect" option for the optimus graphics, which presumably turns optimus off if a non-Windows OS is booted. I haven't tried it yet, maybe somebody else can chime in.

W520 with discrete only idles at 20-25W here, thats not too bad.