Hi,
I just setup multiple monitors on my slackware box. I have a ATI Rage 128 Pro 32MB AGP card that is my main card and has decent hardware accelleration. Today I just put in an old SIS 6236 8MB card for the other head, and I run them both at 1280x1024 resolution. I realized that now that I have both cards enabled I can no longer use hardware accelleration on my ATI card. I do not believe the SIS card has hardware accelleartion, although it might, I dont know, and I wasn't planning on ever using it. Hardware accelleration on the ATI card worked fine before I started using both the graphics cards in X. I looked at X's log and I found some errors about DRI not starting or something, I was wondering why having multiple monitors would make my DRI not work on the main monitor... does anybody know why this is, and/or how to fix it? I would much like to atleast just have say, the other card just turn off or something when I want to play a 3D accellearted game. When I do glxgears it's running really slow, as it would in software rendering mode from the ATI card, and the gears don't even show up if i run them on the other monitor. If anybody has any information on this subject, it would be much appriciated, I'd really hate to have to kill Xorg and swap the xorg.conf's everytime I want to play a 3D game.

Thanks,
Marshall

If you want dual monitors and 3D acceleration, you need a shared framebuffer.

I see your future -- it's an Nvidia card and TwinView, and the ATI card is sitting in the trash.

I'm not looking to spend any more money on this machine, it's my old 300MHz PII box slapped togather with spare parts. I'm looking to build a brand new comptuer soon anyway, so I'll spend money on that to get it hooked up nice with a dual headed card, but I wont buy that for this old thing. As for shared framebuffer, could do that without buying any more hardware?

Only if you can get a different video card for free - then you won't have to buy anything.