ATI Drivers and Lenovo T400 - New Developments

[Christopher A. Williams]

Due to some instability issues I've had recently with Intel drivers and
compiz (these are known), I decided to switch my Lenovo T400 over to
Discrete Graphics mode and run with ATI for a while. In the process, I
found something interesting.

First, as is already known, neither the current OpenSource ATI drivers
currently support 3D accelerated graphics on this chipset (ATI Radeon
HD3400). You still only get 2D. But what was interesting is that I could
get higher video resolutions than I thought possible by using the Radeon
HD driver.

This ThinkPad display is only supposed to support a maximum video
resolution of 1440X900, which also reportedly is its native resolution.
Moreover, the Radeon HD driver does not properly set video resolution to
begin with (using system-config-display). This is partly how I stumbled
across what I did. By editing xorg.conf, I found that I could use it to
set a default maximum resolution of 1440X900.

However, I found afterwards that I could then use the Screen Resolution
applet (System --> Preferences --> Hardware --> Screen Resolution) to
then set video resolutions that are much, much higher. I could go all
the way to 2560X1600 (in 16:9 format) via this route if I wanted to,
although I admit this is amazingly small on a 14" screen. You'll need a
microscope to see it.

I never liked 1440X900 on this machine anyway, so I welcomed being able
to take advantage of the extra "screen real estate" 1680X1050 provides.
But I don't understand why I can't set this resolution by default in X.
Also, the regular OpenSource ATI driver refuses to go beyond 1440X900
under any circumstances.

Does anyone have an explanation as to how and why this is possible with
Radeon HD, but not the regular ATI driver? I'm assuming that the Radeon
HD3400 will be supported in 3D Accelerated graphics mode soon by both of
these, and perhaps ATI will finally get its act together with the fglrx
drivers so they can be properly packaged without violating F10 packaging
guidelines.

In the meantime, I found this to be curiously interesting. Any ideas?

Cheers,

Chris


--
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"Behind every double standard
lies a single hidden agenda."

--G. K. Chesterton