ATI Radeon CrossFire On Linux

[AnObfuscator]

My big questions: does it support multiple monitors in CF mode? how does performance scale in CF/multi-head?

I can't wait to ditch my shitty 8600GTs for GPU's with decent 2D. :-)

[forum1793]

What problems are the 8600gt having? I was thinking of buying one. Nevermind this is wrong thread for that.

[AnObfuscator]

What problems are the 8600gt having? I was thinking of buying one. Nevermind this is wrong thread for that.

http://phoronix.com/forums/showthread.php?t=11044

[SeanBest]

Ok, I was able to set up Crossfire, but I can only set the fan speed on the first card, how can I set the fanspeed on the second card and is there a way to have the changed fan speed set permanently without flashing the BIOS? My Crossfired 4870s get way way way too hot without fan speed set higher.

[cjr2k3]

Is crossfire working for any OpenGL app or only for a few selected? I want to know how much I'll benefit from crossfire in Wine for example.

[bridgman]

AFAIK Crossfire is only enabled for specific apps

[octapult]

Hello bridgman. If crossfire support is enabled succesfully, will there be any "Crossfire Enabled" message in /var/log/Xorg.0.log?.

I still get following messages in my /var/log/Xorg.0.log in both Gentoo X86_64 and Ubuntu interpid X86:

(II) fglrx(0): ATI Video BIOS revision 9 or later detected
(II) fglrx(0): MultiAsic found: Check whether two adapters have the same configu
ration
(II) fglrx(0): ATI Video BIOS revision 9 or later detected
(II) fglrx(0): MultiAsic found: Check whether two adapters have the same configu
ration
(II) fglrx(0): ATI Video BIOS revision 9 or later detected
(II) fglrx(0): MultiAsic found: Check whether two adapters have the same configu
ration
(II) fglrx(0): ATI Video BIOS revision 9 or later detected
(II) fglrx(0): MultiAsic found: Check whether two adapters have the same configu
ration
(EE) fglrx(0): Can't downgrade to required crossfire configuration, disable CF

aticonfig --lsa does show that there are 2 4870 gpu in my system.

octapult@octapult-desktop:~$ aticonfig --lsa
* 0. 03:00.0 ATI Radeon HD 4870 X2
  1. 04:00.0 ATI Radeon HD 4870 X2

* - Default adapter

This is what I get when I enter "aticonfig --lscc":

Master adapter:  0. 03:00.0 ATI Radeon HD 4870 X2
    Candidates:  none

And there is no /dev/dri/card1 in my system:

octapult@octapult-desktop:~$ ls /dev/dri
card0

I can't get temperature of my 2nd gpu:

octapult@octapult-desktop:~$ aticonfig --adapter=1 --odgt
ERROR - Get temperature failed for Adapter 1 - ATI Radeon HD 4870 X2

I suppose those messages are indicating that the Crossfire support is not enabled and the 2nd gpu is not properly set up on my 4870x2?

p.s. Crossfire does work fine in my Windows XP.

[bridgman]

Not sure but will ask. Your first question pretty much exhausted everything I know about Crossfire on Linux

[cjr2k3]

Brigman, I read in http://www.hardwaresecrets.com/article/391/5 that exists several ways of crossfire working, is that the cause of crossfire being only available to a certain application (since load balancing must be calculated)? Or is that because of application specific hacks that the drivers have?

Wikipedia says that ATI Crossfire does have a "dumb" mode (The scissor one) that splits each frame in half in case Catalyst doesn't have a profile for the game. Which mode is implemented in FGLRX? There is a any roadmap for full app support for crossfire in Linux?

Thx in advance.

Sorry for all the questions, but I really would love to understand what is behind Crossfire, since as a Programmer I doesn't see what is the problem of creating Crossfire support in a driver, but, as outsider there must be something that I don't know and AMD Engeeniers do know better that me!