ATI Radeon vs nVidia 3D accelleration

[Marko Vojinovic]

On Friday 12 February 2010 01:04:37 Don Quixote de la Mancha wrote:
> This is very odd: on my F11 box at home, with the Radeon card...
> 
> > You can check for direct rendering like this:
> >
> > glxinfo | grep direct
> >
> > If it says "yes", then all should be well. :-)
> 
> Indeed it says yes, and "glxinfo | less" shows lots of GLX extensions.
> 
> lsmod shows that the radeon and drm kernel modules are loaded, and
> that the radeon module depends on the drm module.
> 
> But when I run Extreme Tuxracer, I get a message box that says:
> 
> "Your system currently is not capable of hardware accelerated 3D.
> Therefore etracer cannot run."
> 
> "Usually the cause of this error is that there are no Free Software
> drivers for your graphics card, please contact your graphics card
> manufacturer and kindly ask them to provide Free Software support for
> your card."
> 
> My card is a 1 GB "ATI Technologies Inc RV770 [Radeon HD 4870]".
> 
> Note that my driver is "radeon" and not "radeonhd".  Is the "hd-less"
> radeon driver also closed-source?

No, radeon is the open source driver, the closed source one is called catalyst 
(once known as fglrx). It seems it is available for F11 in rpmfusion, but not 
for F12 as it doesn't support the F12 version of X.

AFAIK, the radeon driver doesn't support 3D acceleration for HD4*** family of 
cards. and that is probably the reason why tuxracer doesn't work. However, I 
don't know why glxinfo reports that direct rendering is active in this case.

> If Extreme Tuxracer won't run without a Free driver, why would it do
> so well with the very non-Free nvidia driver on my work box?

The tuxracer (or any other app for that matter) doesn't know and doesn't care 
whether the video driver is open source or closed source. It tries to use the 
standard interface extensions for 3D, and X tells it what is available and 
what isn't.

The warning from tuxracer about asking for Free Software support is just a 
message that reflects the programmer's belief/preference in what kind of 
drivers should be provided in Linux generally. The tuxracer itself should run 
with both open source and closed source driver, if they both provide necessary 
functionality. In fact, it is quite impossible for an application to check 
whether the source code for some driver is licensed in this or that way. 
Open/closed source is a human, social concept. The machine doesn't know and 
doesn't care about that.
 
Best, :-)
Marko