I have two identical Samsung monitors. One is connected
to my motherboard VGA port (and appears as a Radeon HD 4200).
The other is connected to a VGA port on a separate PCI Radeon
9200 PRO board.
When I first installed Suse 11.3, I had to go through the nomodeset boot
command (otherwise my system froze up on boot) and I only get
video on the screen connected to the motherboard. The other monitor light
flashes which means it’s not seeing a video signal. And, I do not have an
xorg.conf file in /etc/X11.
So I did the following:
I did an Xorg -config which created an xorg.conf.new file which looked
sensible in that it showed both Radeons, and appeared to set up a dual-head
system. The only change I made was to change the driver for both controllers
from radeon to radeonhd. Then, I copied xorg.conf.new to /etc/X11/xorg.conf
and rebooted. And, nothing is changed. I still need to do nomodeset on
boot and I still only get video on the screen connected to the motherboard.
I’d attach the xorg.conf and Xorg.0.log files, but it says I can’t add attachments
to this post. I don’t see any major errors in the Xorg.0.log file, but a lot of it
is greek to me.
As far as I understand, dual head is two monitors on the SAME video card, not two different video cards, each with its own monitor. Disable the internal video card you called a Radeon HD 4200 and connect both monitors to the PCI Radeon 9200 PRO video board. If the problem is you do not have a DVI to VGA adapter, you need to go buy one, like at Best Buy. This will be the most simple approach to what you are trying to do. In order to use two different video cards will require perhaps loading two different video drivers and in any event, using two monitors is better handled on one single video card.
OK – but it worked fine under 11.2. At that time I had the same PCI 9220 PRO
board but my old motherboard had an nvidia driver. The motherboard died and
had to be replaced.
Even if I disable the motherboard video and just go with the PCI 9200 card (which
has a DVI and VGA output), can I be sure that they are independent video outputs?
I want (and had under 11.2) an xinerama display (not two screens with the same display).
All current video cards support dual head setup. Your options are clone (but reduced to the lowest supported resolution on both monitors, but not a problem when they are identical), twinview (where one monitor becomes the absolute or primary and the other is placed above, below, on the left or on the right of the primary monitor area) or a single monitor where one is on and one is disabled (but you select which one works).
The exact terminology can vary, but they are all doing the same basic thing as above. In twinview, you can put some windows in one monitor and other windows in the other monitor. While playing games might benefit from even more monitors, general productivity tops out at two monitors around 24-26 inches in size (assuming they are not a long distance away from the user).
Another thing to consider is the video driver installed. Generally, you benefit from installing the proprietary video driver from nVidia or ATI and have more options than when only using the default driver. I am not the expert on ATI (or AMD) however and you may need to look around for that advice as I only use nVidia myself.
I did try downloading the proprietary driver from ATI – it caused my system to crash. Took
me a while to find out how to get rid of the driver. But I’m not trying to do anything
fancy – this is the computer I use for work – no games. The most advanced thing
I do on it is probably to download an image or a video. Mostly just text windows. It’s
just a help to be able to have twice the available real estate to have windows open.