[TriLUG] Is it possible to drive a Radeon HD 4290 and GeForce GTX 550 Ti at the same time?

Rob Fitch rafitch71 at gmail.com
Fri Dec 2 14:18:05 EST 2011

Hello and thank you for taking the time to review my case,

What I have:
Gigabyte motherboard with integrated HD 4290 video consisting of a VGA
port, DVI port and HDMI port.
I am running Fedora15 and currently at the kernel.
I am using the ati driver that comes with Fedora15. I haven't looked up
what version it is.

What I added:
GeForce GTX 550 Ti to PCI slot. The card has dual DVI ports and a mini HDMI
I am currently using the 280.13 driver.

What I want to do:
I want the HD4290 to run the display to my monitor. The GTX 550 Ti was
added just to do GPU computing on BOINC projects.

The problem:
I do not know how to configure xorg.conf, if it can even be done, to load
both the ati module and the nvidia module. I can get
the display to run off the HD4290 but then the nvidia module does not load.
I currently have the display running off the GTX550Ti
and the ati module won't load. When I have time I have been querying Google
but the responses end up being for Windows
machines or seemingly indecipherable. Instructions for dual displays under
X have been geared toward single cards with dual
display capability. I have not found instructions for dual displays using
different brands of cards with different drivers.
I admit my time is limited and I may not be using the best queries. I have
been running the display off the GTX550Ti so the GPU
computing will run and periodically tweaking the xorg.conf to test
different configurations but obviously without success.

The reason I consider this a problem:
I wanted the 550Ti to just work on GPU computing projects. The way it is
currently configured, GPU computing projects have to compete with my normal
use. If I'm playing a game or doing any video editing or anything
graphics-intensive it is all processed through the 550Ti. I'd rather keep
the 550Ti exclusively for GPU computing.

This is all my personal preference, not a necessity. If it can't be done,
I'm OK with that, but I'd like to exhaust all options before throwing in
the towel. I am, after all, donating my machine for computational projects.
I think they'll understand if they don't get 100% of my machine. I just
don't like wasting a perfectly good video capability if I don't have to or
interfering in computations that could lead to a scientific breakthrough.

Thank you,
   Rob F.

America's leadership must be guided by the lights of
learning and reason or else those who confuse rhetoric
with reality and the plausible with the possible will gain
the popular ascendancy with their seemingly swift and
simple solutions to every world problem.

----- President John F. Kennedy
Remarks Prepared for Delivery at the Trade Mart in Dallas
November 22, 1963

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