Current support and roadmap for discrete graphics card hot switching

[Albert Vilella]

Hi all,

What is the current support and roadmap for discrete graphics card hot
switching in Xorg?

See:

https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/312756

http://forum.notebookreview.com/showthread.php?t=258304

Hybrids with the Ability to turn off the 3d chip:

AMD/ATI calls it PowerXpress and Nvidia HybridPower. It uses 2 graphics
cards, one energy efficient with little 3d power and the other for gaming
(fast and uses more/a lot of power), the user can choose which chip to use.
This is not a new concept. Sony has build in 2 graphics chips into some of
their laptops for years. In the past a reboot was required to switch between
the chips. With the new generation it is possible to change between chips on
the fly, the screen will flicker but no need to reboot. At least in Windows
Vista (XP, Linux not supported) the user can switch freely between the chips
or set up a profile to do so automatically (eg when on battery use low power
chip and when plugged in use the more powerful chip).

The graphic card hybrid not only works with two Nvidia or AMD cards but the
low power Intel graphics solutions (mostly shard memory) can also be
combined with 3d chips from AMD or Nvidia. This solution is ideal for users
who want maximum battery life and be able to play current games. The most
likely combination is Intel shard memory graphics card for battery life and
some low to mid level 3d chip. This will not give great 3d performance but
enable you to play some games.

Limitations are the drivers. Special drivers are needed depending on which
graphic chips are combined in the hybrid. This will most likely make you
depended on the Notebook manufactures driver support. It is uncertain if 3rd
party drivers (such as laptopvideo2go) will be usable.

One of the models is the Sony Vaio Z series. Right now, both cards are
visible under Linux, but there is no way to hot-switching-off (if that is a
word...) the Nvidia card. For a summary of users' experimentation with this
laptop and Linux.

There are currently ~40 users of Sony Vaio Z series using Linux that would
like this feature to be implemented. See:

https://launchpad.net/~sony-vaio-z-series<https://launchpad.net/%7Esony-vaio-z-series>

Also, see:

http://forum.notebookreview.com/showthread.php?t=325616&page=1
http://forum.notebookreview.com/showthread.php?t=325616&page=2
http://forum.notebookreview.com/showthread.php?t=325616&page=3
http://forum.notebookreview.com/showthread.php?t=325616&page=4
http://forum.notebookreview.com/showthread.php?t=325616&page=5
Thanks,

    Albert.
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