I have a laptop with two video cards:
> lspci|grep -i vga
00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09)
01:00.0 VGA compatible controller: ATI Technologies Inc NI Whistler [AMD Radeon HD 6600M Series] (rev ff)
I have looked around and I saw there is the vgaswitceroo module which can be used in order to turn on/off unused graphics cards and also switch the enabled one (albeit with X restarting).
I believe Ubuntu should power off the unused card by default.
The default behavior is to use the Integrated GPU (Intel) but still keeping the Discrete GPU (ATI) on.
This can save up to 10W in my laptop, which is at least 50% more battery power previously wasted on keeping an unused GPU on.
Best regards,
Nikos
---
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.24.
ApportVersion: 1.23-0ubuntu4
Architecture: amd64
ArecordDevices:
**** List of CAPTURE Hardware Devices ****
card 0: PCH [HDA Intel PCH], device 0: ALC269 Analog [ALC269 Analog]
Subdevices: 1/1
Subdevice #0: subdevice #0
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/controlC0: andrikos 3587 F.... pulseaudio
Card0.Amixer.info:
Card hw:0 'PCH'/'HDA Intel PCH at 0xf7d00000 irq 48'
Mixer name : 'Intel CougarPoint HDMI'
Components : 'HDA:10ec0269,104d5300,00100004 HDA:80862805,104d5300,00100000'
Controls : 17
Simple ctrls : 9
DistroRelease: Ubuntu 11.10
HibernationDevice: RESUME=UUID=2a386f35-058c-4b56-a4ef-086a54f6b10e
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Release amd64 (20111012)
MachineType: Sony Corporation VPCCB2S1E
Package: linux (not installed)
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.0.0-17-generic root=UUID=30b47f3a-9136-4791-a5c8-f72e6b1c7362 ro quiet splash vt.handoff=7
ProcVersionSignature: Ubuntu 3.0.0-17.30-generic 3.0.22
RelatedPackageVersions:
linux-restricted-modules-3.0.0-17-generic N/A
linux-backports-modules-3.0.0-17-generic N/A
linux-firmware 1.60.1
StagingDrivers: mei
Tags: oneiric running-unity staging
Uname: Linux 3.0.0-17-generic x86_64
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm admin cdrom dialout kismet lpadmin plugdev sambashare
dmi.bios.date: 04/15/2011
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: R1100V2
dmi.board.asset.tag: N/A
dmi.board.name: VAIO
dmi.board.vendor: Sony Corporation
dmi.board.version: N/A
dmi.chassis.asset.tag: N/A
dmi.chassis.type: 10
dmi.chassis.vendor: Sony Corporation
dmi.chassis.version: N/A
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrR1100V2:bd04/15/2011:svnSonyCorporation:pnVPCCB2S1E:pvrC6099RLH:rvnSonyCorporation:rnVAIO:rvrN/A:cvnSonyCorporation:ct10:cvrN/A:
dmi.product.name: VPCCB2S1E
dmi.product.version: C6099RLH
dmi.sys.vendor: Sony Corporation
In order to get this behavior we can have a solution as described here:
http://