Multi-Head Displays in Linux - page 2
IntroductionMulti-head displays in Linux are fairly easy to set up, assuming you have the correct software. In order to run a multi-head display, you first need an X server which supports multiple monitors (the standard XFree86 126.96.36.199 won't do it). XFree86 4.0, due out later this year, promises to include multi-head support, but until it is released the only recourse is to purchase a commercial server. Two such servers are Metro-X and AcceleratedX.
AcceleratedX is the powerful X server
from Xi Graphics, so named
because it is reputedly faster than XFree86 on most video adapters.
Unfortunately, in order to run a multi-head system with this server, it is
necessary to purchase a special edition of it for approximately three hundred
dollars. In addition, there is no configuration utility that can deal with
setting up multiple monitors, so adding a second screen to your system requires
editing the configuration text file by hand.
Metro-X from Metro Link Incorporated, by
comparison, has only four video cards available for multi-head setups (although you can install them
in different configurations). However, the asking price ($39) is more than low enough to warrant spending a little more on hardware. Because I already owned
one of the cards which Metro-X supports (a Matrox Millennium II), I decided to
give their server a try.
Setting up Metro-XOrdering the Metro-X server from Metro Link's web site was easy enough, as was installing the RPMS I found on their secure FTP site. The installation is robust -- it replaces your current XFree86 setup without deleting your old configuration files, which puts you in a position to start working again immediately should you decide to un-install Metro-X later. Especially ingenious is the Metro-X setup utility, which lets you graphically configure all of your monitors and video cards, as well as how monitor orientation is to be treated by the server (Figure 1).
At first I was somewhat miffed, as I was unable to start the X server, receiving
only a blank screen for my efforts. However, checking the Metro-X FAQ, I
found that the solution was to turn off VGA mode for my second video card (a
Matrox Millennium). Kudos to Metro Link for the robust documentation.
Once the server was up and running I had few problems, with the possible exception of problems popping up after leaving the server on for a long period of time. After a day or two, the window manager started mishandling window events causing annoying, random bugs. This seems to be due to some sort of memory leak in the server.