Difference between revisions of "Switchable Graphics"

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With newer laptops based on the Intel [[Centrino]] 2 platform (codename [[Montevina]]) switching between a weak, low power consumption integrated GPU and high performance dedicated GPU is possible with laptops with the feature enabled.  Some examples are the {{R400}}, {{T400}}, {{T500}}, {{w500}}.  Note that this feature is not available on any X or SL series laptop.
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Select ThinkPads feature switchable graphics, where a low power consumption integrated GPU and high performance dedicated GPU is combined and you have the ability to switch between them, sacrificing either performance or battery life.
  
In Linux, switching graphics has to be done in the BIOS. 
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In Windows XP this switching requires a logout/login, while in Vista and Windows 7 there is support for runtime switching.
In Windows, only Vista currently has drivers that allows on the fly switching. To do so, you need to have the power manager installed and running (Version 2.41a tested), then right-click on the green battery simbol (not the one from Vista) and choose the high or low power gpu under Switchable graphics.
 
  
On Ubuntu Intrepid Xorg wouldnt work at all ( vesa, intel and radeon drivers ). BIOS setting has to be either on Internal or External, not Switchable.
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Under Linux, the switching so far had to be done by entering BIOS setup and changing between "Internal" (low power, integrated), "External" (high performance, discrete) or "Switchable" (OS selectable) options.
On Karmic the Integrated Intel card works with both Integrated or Switchable set
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Depending on which Linux version you use, you could have the following effects
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* On Ubuntu 8.10 (Intrepid) BIOS setting has to be either on Internal or External, not Switchable.
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* On Ubuntu 9.10 (Karmic) the Integrated Intel card works with both Integrated or Switchable set
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Lenovo has published a [http://www-307.ibm.com/pc/support/site.wss/document.do?lndocid=MIGR-70495 Switchable Graphics FAQ] you may want to review.
  
 
== Switchable Graphics and Docks ==
 
== Switchable Graphics and Docks ==
  
T400 (and probably other, not verified) laptops with switchable graphics can only drive DVI output in Advanced Mini-dock by using discrete graphics card, integrated GPU is just not attached to DVI output (though VGA output through dock is possible).
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ThinkPads with switchable graphics can only drive DVI or DisplayPort outputs on Docks by using the high-performance discrete graphics card, the integrated GPU is just not attached to the DVI or DisplayPort outputs (though VGA output through the dock is possible).
  
 
== Development status ==
 
== Development status ==

Revision as of 13:44, 1 March 2010

Select ThinkPads feature switchable graphics, where a low power consumption integrated GPU and high performance dedicated GPU is combined and you have the ability to switch between them, sacrificing either performance or battery life.

In Windows XP this switching requires a logout/login, while in Vista and Windows 7 there is support for runtime switching.

Under Linux, the switching so far had to be done by entering BIOS setup and changing between "Internal" (low power, integrated), "External" (high performance, discrete) or "Switchable" (OS selectable) options.

Depending on which Linux version you use, you could have the following effects

  • On Ubuntu 8.10 (Intrepid) BIOS setting has to be either on Internal or External, not Switchable.
  • On Ubuntu 9.10 (Karmic) the Integrated Intel card works with both Integrated or Switchable set

Lenovo has published a Switchable Graphics FAQ you may want to review.

Switchable Graphics and Docks

ThinkPads with switchable graphics can only drive DVI or DisplayPort outputs on Docks by using the high-performance discrete graphics card, the integrated GPU is just not attached to the DVI or DisplayPort outputs (though VGA output through the dock is possible).

Development status

David Arlie has been working on switching between GPUs without having to reboot, and changing BIOS settings. An initial version of a new driver (vga_switcheroo) has been merged in the 2.6.34 kernel. This driver allows switching between graphics cards, but requires that the Xserver is restarted. Full seamless runtime switching support will require significant Xserver work.

http://www.phoronix.com/scan.php?page=news_item&px=ODAyMg

ThinkPad models which may have this feature