[ltp] Intel video on T420

Martin Steigerwald linux-thinkpad@linux-thinkpad.org
Fri, 16 Dec 2011 17:18:22 +0100

Am Donnerstag, 8. Dezember 2011 schrieb Takis Diakoumis:
> hi

Hi Takis!

> i'm about to upgrade my T61 to a T420. i currently have nvidia graphics
> which has been good and bad. i have been running debian wheezy and will
> do so on the new one too.
> i'm looking at the T420 with intel graphics. i have read that 3D
> support is complete and working on various threads from this one,
> thinkwiki and some others. some ambiguities remain however (the gentoo
> docs have been especially helpful) and i just thought i'd ask one more
> time - so a simple yes or no, is 3D support fine out-of-the-box for
> intel graphics? ...specifically gnome3 has grown on me and i am
> curious of any experiences with gnome3 using intel video.

Yes for KDE 4.6.5 and 4.7.2 with compositing on a ThinkPad T520. Rock=20
stable and really nice.

Partly yes for games. Its astonishing how much fps the Intel developers=20
squeezed out of the Sandybridge onboard graphics in the meanwhile and AFAI=
think the Debian packagers did not even enable the Sandybridge=20
Acceleration Architecture (SNA), although I didn=C2=B4t check recently.

But there are some issues. Out of my memory:

1) I have to disable compositing in KDE before playing Playstation games=20
in pcsx, otherwise I might get a X.org crash.

2) Supertuxkart sometimes hung for a short while. But this got better=20

Aside from that, its really awesome. I can play lots of games at 1920x1080=
and reasonable framerates. Supertuxkart looks awesome at that resolution.

Regarding multi display setups with XRandR I had some issues as well:=20
Clone mode displayed garbage on the beamer with displayport to DVI=20
adapter, but that might have worked with disabled compositing. Side by=20
side it worked, but on undoing the multi display setup X.org crashed.

=46or energy saving I recommend:

martin@merkaba:~> cat /etc/modprobe.d/i915-kms.conf=20
# Thorsten Leemhuis, Die Woche: Ungenutztes Stromsparpotenzial
# http://www.heise.de/open/artikel/Die-Woche-Ungenutztes-
# Eugeni Dodonov, Intel Linux Graphics
# Following the open source road from Kernel to UI toolkits
# http://www.scribd.com/doc/73071712/Intel-Linux-Graphics
options i915 modeset=3D1 i915_enable_rc6=3D1 i915_enable_fbc=3D1 semaphores=

This is working nicely for me and it saves *a lot*, especially rc6 which=20
might get enabled by default in Linux kernel 3.2.

I bet the Heise article is available in english as well.

Despite those issues this has been my most pleasant open source graphics=20
driver experience so far, even when the ThinkPad T42 is doing quite well=20
with the Gallium based Radeon driver in the meanwhile.

Martin 'Helios' Steigerwald - http://www.Lichtvoll.de
GPG: 03B0 0D6C 0040 0710 4AFA  B82F 991B EAAC A599 84C7