Difference between revisions of "Intel graphics"

Revision as of 03:56, 25 December 2012

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Since Intel provides and supports open source drivers, Intel graphics are now essentially plug-and-play.

For a comprehensive list of Intel GPU models and corresponding chipsets and CPUs, see this comparison on wikipedia.

Installation

Prerequisite: Xorg

Install the xf86-video-intel package which is available in the official repositories. It provides the DDX driver for 2D acceleration and an XvMC driver for video decoding on older GPUs. It pulls in intel-dri as a dependency, providing the DRI driver for 3D acceleration.

If you want to use hardware accelerated video decoding/encoding on newer GPUs, install the VA-API driver provided by libva-intel-driver package also, available in the official repositories.

You may need to install lib32-intel-dri in 64-bit systems to use 3D acceleration in 32-bit programs.

Configuration

There is no need for any kind of configuration to get the X.Org running (an xorg.conf is unneeded, but needs to be configured correctly if present).

For the list of options, type man intel.

KMS (Kernel Mode Setting)

KMS is required in order to run X and a desktop environment such as GNOME, KDE, Xfce, LXDE, etc. KMS is supported by Intel chipsets that use the i915 DRM driver and is enabled by default as of kernel v2.6.32. Versions 2.10 and newer of the xf86-video-intel driver no longer support UMS (except for the very old 810 chipset family), making the use of KMS mandatory^[1]. KMS is typically initialized after the kernel is bootstrapped. It is possible, however, to enable KMS during bootstrap itself, allowing the entire boot process to run at the native resolution.

To proceed, add the i915 module to the MODULES line in /etc/mkinitcpio.conf:

MODULES="i915"

Now, regenerate the initramfs:

# mkinitcpio -p linux

and reboot the system. Everything should work now.

Tips and tricks

Choose acceleration method

The DDX driver allows to preset your desired acceleration method. The default method is UXA, which is more stable but slower than SNA. SNA has improved performance, but still considered experimental. Check benchmarks done by Phoronix [2]. These can be found here for Sandy Bridge and here for Ivy Bridge. UXA is still a solid option, if experiencing trouble with SNA.

If you want to use the new SNA method, create /etc/X11/xorg.conf.d/20-intel.conf with the following content:

/etc/X11/xorg.conf.d/20-intel.conf

Section "Device"
   Identifier  "Intel Graphics"
   Driver      "intel"
   Option      "AccelMethod"  "sna"
EndSection

Setting scaling mode

This can be useful for some full screen applications:

$ xrandr --output LVDS1 --set PANEL_FITTING param

where param can be:

• center: resolution will be kept exactly as defined, no scaling will be made,
• full: scale the resolution so it uses the entire screen or
• full_aspect: scale the resolution to the maximum possible but keep the aspect ratio.

If it does not work, you can try:

$ xrandr --output LVDS1 --set "scaling mode" param

where param is one of "Full", "Center" or "Full aspect".

KMS Issue: console is limited to small area

One of the low-resolution video ports may be enabled on boot which is causing the terminal to utilize a small area of the screen. To fix, explicitly disable the port with an i915 module setting with video=SVIDEO-1:d as you kernel command line parameter in your bootloader. See Kernel parameters for more info.

If that does not work, you may also try disabling TV1 or VGA1 instead of SVIDEO-1.

H.264 decoding on GMA 4500

The libva-driver-intel package provides MPEG-2 decoding only for GMA 4500 series GPUs. The H.264 decoding support is maintained in a separated g45-h264 branch, which can be used by installing libva-driver-intel-g45-h264^AUR package, available in the Arch User Repository. Note however that this support is experimental and not currently in active development. Using the VA-API with this driver on a GMA 4500 series GPU will offload the CPU but may not result in as smooth a playback as non-accelerated playback. Tests using mplayer showed that using vaapi to play back an H.264 encoded 1080p video halved the CPU load (compared to the XV overlay) but resulted in very choppy playback, while 720p worked reasonably well [3]. This is echoed by other experiences [4].

Setting gamma and brightness

Intel offers no way to adjust these at the driver level. Luckily these can be set with xgamma and xrandr.

Gamma can be set with:

$ xgamma -gamma 1.0

or:

$ xrandr --output VGA1 --gamma 1.0:1.0:1.0

Brightness can be set with:

$ xrandr --output VGA1 --brightness 1.0

Troubleshooting

Glxgears shows low performance results

If you run glxgears in order to check your system's graphics performance, you may notice it showing results around 60 FPS. For example:

[...]
311 frames in 5.0 seconds = 61.973 FPS
311 frames in 5.0 seconds = 62.064 FPS
311 frames in 5.0 seconds = 62.026 FPS
[...]

That is not caused by performance regression, but because the system graphics are using vertical synchronization, which is your display's native frames per second.

Disable VSYNC

To disable VSYNC just add in your /etc/X11/xorg.conf.d/20-intel.conf in Section "Device" the string Option "SwapbuffersWait" "false".

Alternatively, set vblank_mode to 0 in ~/.drirc and make sure that driver is set to dri2:

~/.drirc

<device screen="0" driver="dri2">
   <application name="Default">
   <option name="vblank_mode" value="0"/>
   </application>
</device>

Blank screen during boot, when "Loading modules"

If you are using "late start" KMS and the screen goes blank when "Loading modules", it may help to add i915 and intel_agp to the initramfs. See the above KMS section.

Alternatively, appending the following kernel parameter seems to work as well:

video=SVIDEO-1:d

Tear-free video

If you are using the SNA acceleration method, you can get rid of video tearing by adding the following to the Device section of /etc/X11/xorg.conf.d/20-intel.conf:

Option "TearFree" "true"

X freeze/crash with intel driver

If you have issue with X crashing, GPU hang or problem with frozen X, then the fix may be to disable the GPU usage with the NoAccel option:

/etc/X11/xorg.conf.d/20-intel.conf

Section "Device"
   Identifier "Intel Graphics"
   Driver "intel"
   Option "NoAccel" "True"
EndSection

Alternatively, you could try to disable the 3D acceleration only with the DRI option:

/etc/X11/xorg.conf.d/20-intel.conf

Section "Device"
   Identifier "Intel Graphics"
   Driver "intel"
   Option "DRI" "False"
EndSection

Adding undetected resolutions

This issue is covered on the Xrandr page.

Slowness after an upgrade to libGL 9 and Intel-DRI 9

Downgrade to Intel-DRI 8 and libGL 8.

Black textures in video games

If you are experiencing black textures in your video games the solution may be enabling S3TC texture compression support. It can be enabled through driconf or by installing libtxc_dxtn.

This "issue" will be fixed very soon in the newer drivers

You can read more about S3TC at: http://dri.freedesktop.org/wiki/S3TC http://en.wikipedia.org/wiki/S3_Texture_Compression

One of the games that is affected by this issue is Oil Rush

See also

• http://intellinuxgraphics.org/documentation.html (includes a list of supported hardware)
• KMS — Arch wiki article on kernel mode setting
• Xrandr — If you have problems setting the resolution
• Arch Linux forums: Intel 945GM, Xorg, Kernel - performance