OpenGL not functional, glxgears produces black screen. How to debug?

[BicyclerBoy]

Did not say it would not work (using 6600).

But the 6600 was never doing any openGL computation, all the openGL runs in the one card (unless SLI).
SLI requires both cards to be same /very similar so forget the 6600.

Using the 6600 prob just lowers the max frame rates.

AFAIK Xorg xinerama breaks nVidia openGL (version 173 to 295 appox).
Certainly breaks composite extension.
Xorg xinerama is not same as nVidia xinerama extension.

Comments about dissimilar GPUs:
http://us.download.nvidia.com/XFree8...neramaglx.html
Check your /var/log/Xorg.0.log

The fermi & kepler cards have >=3 monitor jacks.
Some of the kepler cards can drive 4; prob because the comparative AMD can.

[kerryhall]

I would like to be able to drive 4 monitors at some point, but only worries about the 3 atm.

I see that SLI is out, but it sounds like that is ok.

I'm ok with the lower frame rates from using the 6600.

My goal is simply: play Openarena across all three monitors with current hardware setup. If you can get me up and running I will paypal you $20.

I have the xinerama box ticked in nvidia-settings, not sure if that is xorg xinerama or nvidia xinerama.

Thank you for the assistance, I will post relevant output from /var/log/Xorg.0.log tonight.

[BicyclerBoy]

AFAIK nVidia has made significant changes to twinview with this driver version..the readme does not seem to reflect these changes..
Unfortunately only the driver release "highlights" tab contains the change detail.
There does not seem to be any change summary vs driver version..

As you using latest driver this link is better:
http://us.download.nvidia.com/XFree8...gtwinview.html

http://us.download.nvidia.com/XFree8...neramaglx.html

And check the log file for error/warnings

Is your GL/GLX installed ?
glxinfo | grep OpenGL
should be noted in the log file as well..

[kerryhall]

I think I found the key line:

"Using identical GPUs is recommended. Some combinations of non-identical, but similar, GPUs are supported. If a GPU is incompatible with the rest of a Xinerama desktop then no OpenGL rendering will appear on the screens driven by that GPU. Rendering will still appear normally on screens connected to other supported GPUs. In this situation the X log file will include a message of the form"

So yeah, I need "similar" GPUs for Xinerama across cards! I will check the logs when I get home tonight, but I think the solution here is either "troll nvidia devs" or "buy new video card(s)"

Ugh! Thanks for your help though. I'm going to dig a little bit deeper. If I can't get openarena working I will still paypal you $10 for your assistance.

[kerryhall]

[ 19.528] (WW) NVIDIA(1): The GPU driving screen 1 is incompatible with the rest of the
[ 19.528] (WW) NVIDIA(1): GPUs composing the desktop. OpenGL rendering will be
[ 19.528] (WW) NVIDIA(1): disabled on screen 1.

*facepalm*

Ugh.

Looks like I need to just buy two new video cards. What a stupid issue. pm me your email and I'll paypal you $10 for your assistance.

[BicyclerBoy]

I don't require any payment..glad to help.

AFAIK With linux/X server it is easier to get the performance from one card.
Unless you have a known working soln with twin cards, I would buy a GTX660Ti or better.
Note: one output is displayport.

AFAIK Dual cards in SLI requires working mobo soln as well as the driver etc..

[kerryhall]

Thanks again!!

As an item of note: I was able to play openarena across all three monitors in windows 7 on the same machine, so it's not a hardware issue. Rather, it appears to be a limitation of the Linux driver.