CentOS - Jul 2008 - Dual video card, 1 monitor each (ref dual head) CentoS4.6 xorg does only 1 head

I need to start running a dual head on one of my machines. Eventual
target is CentOS 5.x. Decided to test first on my 4.6 setup (eventually
it will achieve 5.x). Both machines are fully up to date.

The test machine is 4.6, 2 radeon video cards. Searched the web, CentOS
site, even bugzilla. This bugzilla entry from a 4.2 system),
http://bugs.centos.org/view.php?id=1875
had only a WFM response.

I've attached a gzipped text file of pertinent information.

Briefly, kudzu did the right thing when I installed the second card.
System-config-display also behaved correctly. X start ok, but will only
use one head at a time. Adding a second "BusID" so that both cards are
explicitly addressed didn't help. When the 2 "BusID" entries are
switched, the active screen doesn't move (it's always
"Screen0") and the
ignored screen ("Screen1") remains the same. The monitor attached to
the
video card for "Screen0" becomes the active one.

Q1: Anyone have a two video card CentOS 4.6 setup working?

Q2: Is it working in CentOS 5?

Q3: Anyone see something I'm doing wrong? Suggestions?

TIA,
-- 
Bill
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On Tue, 22 Jul 2008 06:03:16 -0400
"William L. Maltby" <CentOS4Bill at triad.rr.com> took out a #2
pencil
and scribbled:
> I need to start running a dual head on one of my machines.
> Eventual target is CentOS 5.x. Decided to test first on my 4.6
> setup (eventually it will achieve 5.x). Both machines are fully
> up to date.
> 
> The test machine is 4.6, 2 radeon video cards. Searched the web,
> CentOS site, even bugzilla. This bugzilla entry from a 4.2
> system), http://bugs.centos.org/view.php?id=1875
> had only a WFM response.
> 
> I've attached a gzipped text file of pertinent information.
> 
> Briefly, kudzu did the right thing when I installed the second
> card. System-config-display also behaved correctly. X start ok,
> but will only use one head at a time. Adding a second "BusID" so
> that both cards are explicitly addressed didn't help. When the 2
> "BusID" entries are switched, the active screen doesn't move
> (it's always "Screen0") and the ignored screen
("Screen1")
> remains the same. The monitor attached to the video card for
> "Screen0" becomes the active one.
> 
> Q1: Anyone have a two video card CentOS 4.6 setup working?
> 
> Q2: Is it working in CentOS 5?
> 
> Q3: Anyone see something I'm doing wrong? Suggestions?
> 
> TIA,
This was addressed on the list at one point, and marked as solved
by the poster. 

http://lists.centos.org/pipermail/centos/2007-May/080915.html

Does this help you out? I haven't had occasion to play with dual
head yet.

A quick google also turned this up, but it is not directly related
to CentOS, I run an nvidia card and can't speak to how well this
would work for you.

http://www.linuxine.com/2008/06/how-to-enable-dual-monitors-with-ati-diplay-card-in-linux.html

Mind the line wrapping.

HTH

Alex White

-- 
ethericalzen at gmail.com
Life is a prison, death is a release

On Tue, Jul 22, 2008 at 06:03:16AM -0400, William L. Maltby
wrote:
> Q1: Anyone have a two video card CentOS 4.6 setup working?
A few years ago I worked on a setup for an accelerator control room where 
multi-monitor was essential. After many iterations, we settled on nVidia NVS 
400 quadro cards, a couple machines having 2 of these cards and driving 8 
monitors (@ 1280x1024 that's 5120x2048 desktop).  All this was on SL 4.2 I 
think.

During testing with various cards (Matrox, ATI Radeon, nVidia) I do recall 
having all sorts of problems getting 2 ATI cards to work together in one 
machine. I think I eventually found some documentation (not sure where :-( ) 
that pointed to an issue where the second ATI card did not initialize 
properly. In fact, I seem to recall an ATI card would not initialize properly 
unless it was the primary video card, ie the ATI Radeon 7500 PCI needed to be 
set as primary in the bios over the Matrox G450 AGP in order for both to 
work.
> Q2: Is it working in CentOS 5?
Did not try, and now am in a new job.
 
> Q3: Anyone see something I'm doing wrong? Suggestions?
After testing the nVidia NVS 400's and settling on them, I did not pursue
any
further. Sorry.

Good luck.
Chris
--
Chris Payne			chris.payne at triumf.ca
TRIUMF ATLAS Tier-1 System Administrator - Networking
TRIUMF				+1 604 222 7554
4004 Wesbrook Mall, Vancouver, BC, V6T2A3, CANADA