GPU Runtime Power Management Coming For Linux 3.12

[phoronix]

Phoronix: GPU Runtime Power Management Coming For Linux 3.12

The latest DRM subsystem work to be merged for the upcoming Linux 3.12 kernel is runtime power management support to be able to dynamically turn on/off secondary GPUs. This is an especially important feature for those with dual GPU (e.g. Optimus) laptops where the secondary GPU doesn't need to be constantly running...

http://www.phoronix.com/vr.php?view=MTQ0ODM

[schmidtbag]

Does this happen to work on desktop GPUs too? While I'm intending to switch to radeon as soon as it gets crossfire support, I might just make the switch anyway if I can shut off my 2nd GPU. So far the Heaven benchmark is the only thing I have in linux that uses crossfire. Right now the only compelling reason for me to stick with catalyst at this point is the better performance and better-implemented openGL.

[halo9en]

Correct me if I'm wrong... so this is only for nouveau, and it also removes vga_switcheroo userspace support?

[Adarion]

To me it sounds like something basic that sooner or later could be used by any driver that is aware of a multi GPU situation. Would be marvellous if that worked on laptops and desktop mainboards.

[canezila]

Hope it is also working with dual AMD/ATI GPUs on laptops. I wasnt sure if they were just talking nvidia or amd as well.

[abral]

Does this mean that now nouveau supports optimus?

[dffx]

Does this mean that now nouveau supports optimus?

It's not nouveau that needs to support Optimus, it's X. And it does, as of Xorg 1.14 (with Xrandr 1.4) via PRIME offloading. It works for both AMD and Nvidia hybrid graphics:

~ $ glxinfo | grep render
direct rendering: Yes
OpenGL renderer string: Mesa DRI Intel(R) Ivybridge Mobile 
    GL_NV_conditional_render, GL_NV_depth_clamp, GL_NV_packed_depth_stencil, 
    GL_NV_conditional_render, GL_NV_depth_clamp, GL_NV_light_max_exponent, 
~ $ DRI_PRIME=1 glxinfo | grep render
direct rendering: Yes
OpenGL renderer string: Gallium 0.4 on AMD PITCAIRN
    GL_MESA_window_pos, GL_NV_blend_square, GL_NV_conditional_render,

My question, on this GPU power management, is whether this works for both Nvidia *and* AMD cards. I imagine it would?