Comment 54 for bug 541492

On Thu, Apr 15, 2010 at 1:26 PM, jerrylamos wrote:
> Geir,
> i845 with
> i915.modeset=0
> xorg.conf
> Section "Device"
>        Identifier      "Configured Video Device"
> #       Driver          "vesa"
>        Driver          "intel"
>        Option          "DRI" "Off"
> EndSection
> and kernel 2.6.32-21 with xserver-xorg-video-intel 2:2.9.1-3ubuntu3
> stayed up all night.  Previously without the Option it black screened in a half hour.
> GtkPerf was 46.69 seconds much slower than "vesa" with 34.29 seconds.

So in this case, turning DRI off in xorg.conf actually made a
difference, even though it is already disabled. This suggests that the
disabling is not done in the right place. Could you attach your
Xorg.0.log from this session here (which is now Xorg.0.log.old if you
restarted xorg once since you ran this)? I would like to see how the
DRI disabling messages interact.

> What benefit do I get for my application centered operations is there
> with video intel which is by that measure 36% slower than vesa?

For you there will apparently be no reason to run with intel, since
vesa is much better. But then, I suppose you help us with this in
order to help everyone else running ubuntu :-)

The main problem with the VESA driver is that it has a very limited
set of resolutions available. If the native resolution of your monitor
is one of those, then fine. The VESA resolutions are all in 4:3
format, so nobody with a 16:9 monitor will be able to use the native
resolution. I think also high-resolution monitors will have problems.
This is the main reason we don't want to use VESA by default.