Announcement

Collapse
No announcement yet.

Today, Delayed GPU Switching Comes To Linux

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • #16
    Originally posted by iVistux View Post
    If we should be able to switch GPUs online without restarting X, this would enable Linux-Systems to impress (Windows needs special drivers because it can not run multiple GPU-drivers, we can).

    Being able to do this on every system that has multiple GPUs would be a killer feature, because a lot of systems at all have IGPs and desktop systems with dedicated graphic cards could use this to save energie.
    I agree. Switching GPUs while X is running would be quite a feat, but it's also probably a very difficult feat to achieve. You'd have to get every running 3D program migrated over, which might not be possible (e.g. if you were running an OpenGL 3.x application and then switched back to integrated graphics with less capabilities).

    That being said, I just wanted to point out that while Windows Vista could only support video drivers from one company running at a time on a given system, Windows 7 has the ability to run drivers for multiple brands of cards simultaneously. This ability was also (I think) introduced to Vista in Oct 2009 (via the Vista Platform Update). Basically, if your windows computer is running WDDM 1.0 (original vista), you can only run one video driver at a time, if you have WDDM 1.1 (Windows 7, and possibly updated Vista), you can run multiple.

    Comment


    • #17
      Originally posted by RealNC View Post
      How? No one wants to unplug the monitor's cable all the time in order to switch from the external graphics card's VGA/DVI port to the IGP's one. That would be just dumb
      My monitor has VGA and DVI inputs, switching between them is as simple as pressing a button.

      Comment


      • #18
        Originally posted by RealNC View Post
        How? No one wants to unplug the monitor's cable all the time in order to switch from the external graphics card's VGA/DVI port to the IGP's one. That would be just dumb
        I could see a really kludgy workaround where you use a monitor with multiple inputs that auto-senses when its current input disappears and switches to an alternate active input... It's a horrible workaround, but it'd function. And it would completely reintroduce the flicker problem that KMS just solved.

        Comment


        • #19
          My monitor does have DVI and VGA and automatically detects if one goes dead and switches to the other. Problem is, it's not an acceptable solution: I want digital output all the time, not an analog VGA signal.

          Comment


          • #20
            Systems with switchable graphics either (a) include built-in multiplexers to switch the video output connectors from one GPU to the other, or (b) always display from the IGP and copy screen data from the discrete GPU when drawing on the big iron. I don't think you have to move video cables. I hope

            Comment


            • #21
              (b) sounds promising. I wonder if this can be implemented in some part of X for every system.

              Comment


              • #22
                Maybe Gallium could help here. Wasn't there talk of implementing an X state tracker to run X directly on top of Gallium? Then one could probably just swap the GPU driver underneath without X even knowing it?!

                Comment


                • #23
                  I use a dual input for 2 computers on 1 monitor (1xVGA for the old box and DVI for the new box).
                  Iirc the old Voodoo cards had a cable supply that would take in the signal from the standard 2d-VGA card and output it besides the input through VGA out. When they were active they'd switch and put their own signal from 3d gaming to the VGA out. Or course that needs some input on one of the cards.
                  But if it is possible to send the signal from the big card to the onboard unit as bridgman said... I'm not sure if I even had this when I put in my 3870 and had the DVI still on the onbaord 3300.
                  Would be a ready to use soulution then.

                  Comment


                  • #24
                    The switching hardware is built into specific laptops; it doesn't come automatically with every combination of hardware.

                    Comment


                    • #25
                      Originally posted by bridgman View Post
                      The switching hardware is built into specific laptops; it doesn't come automatically with every combination of hardware.
                      Do they offer it then under a special brand name? Is "hybrid graphics" already enough to be sure you have the HW capabilities in there?

                      Comment

                      Working...
                      X