Monday, February 9, 2009

multiseat 3D. denied (for now)

So I've been trying to figure out a way to let my daughter play the "duck game" (or at least watch the penguin drift aimlessly down the hill) while I do whatever else I am doing that is so damn important. Naturally, the first thing a normal person thinks to do is hook up another monitor, keyboard, and mouse to their existing computer. Right? Everyone does this? No.

This is basically the dream. However, to get there from here you need TWO video cards. I have an PCI-Express Nvidia card. So I needed another PCI video card that can do 3D. In case you don't know, PCI is kind-of getting obsolete for video cards these days so it isn't easy to find one. My brother kindly gave me an ATI Radeon PCI something or other. Great! Plug it all in and I'm ready to roll.

Wait. Nvidia ships with proprietary OpenGL libraries. ATI ships with proprietary OpenGL libraries. Damn! You can't mix the two! So I spend $50 on a Sparkle brand Nvidia card just like my PCI-Express version and now I have TWO identical cards except for the interface. And now here is where we come so, so close...

I get it all working. Using the config example earlier I get two logon prompts on two monitors. I can log in on one and on the other. OpenGL games work on both! Most importantly, the Duck Game works! I tried Quake3 but it is pretty darn slow, but that might be related to a serious problem: one of my three cpu cores is completely pegged while the second instance of Xorg is running. I had the same problem with the ATI card (using the free non-GL drivers), so it seems to be an Xorg thing.

Another problem is that I cannot switch consoles (seems you must disable this for dual Xorg instances to work). This means no "switch users" functionality (unless you count logging on to the other monitor). So now it is harder to share the computer with my wife, which is ironic since I doubled the seats! Finally, sleep mode doesn't work so well, coming out goes to a blank screen and seems to be crashed.

So maybe I'll post a bug report to Xorg and these issues can be resolved.. but I sort-of doubt it since there is very little demand for this multiseat business...

** Update**

Xorg version 7.4 provides GLX pass-through-- so I should be able to xephyr and not fuss with xorg instances. This might solve everything....

1 comment:

Joachim Zobel said...


Congratulations and welcome to the club. See