2 GPU PCIe RADEON CARDS like the 6870x2 (PowerColor AX6870X2)

[Viceroy]

Who has a 2 GPU card and has a successful mining rig?  

What is your hardware / software / driver combination?

Does it work as expected?


My step by step guide to building a linux based bitcoin mining machine under centos can be found here.


great OpenCL Reference Link:
http://dhruba.name/2012/08/21/opencl-cookbook-series-reference/

particularly Chapter 11, aka
OpenCL Cookbook: Compiling OpenCL with Ubuntu 12.10, Unity, AMD 12.11 beta drivers & AMD APP SDK 2.7
http://dhruba.name/2012/10/29/compile-opencl-with-ubuntu-12-10-unity-amd-12-11-beta-drivers-app-sdk-2-7/

Ironically Ubuntu doesn't like multiple cards and so it cannot be installed, nor Mint, on a multi GPU system.


REALLY IMPORTANT NOTE ABOUT CATALYST:

As of SDK 2.8, the AMD APP SDK GPU runtime is not supported. To get the APP GPU runtime file,
install the Catalyst driver. The SDK 2.8 runtime supports only CPU hardware; it is installed under
/opt/AMDAPP/

Recommandations for GPU user:
Install 12.10 (or later) Catalyst driver then install SDK 2.8 to avoid the CPU RT files installation.

[Viceroy]

What is your hardware / software / driver combination?

(1) PowerColor AX6870x2
Centos 6.4 (2.6.32-358.2.1.el6.x86_64)
fglrx64_p_i_c.x86_64 (8.951-1)
AMD-APP-SDK-v2.4-lnx64

Does it work as expected?

Working and stable under cgminer.  

Code:

 [P]ool management [G]PU management [S]ettings [D]isplay options [Q]uit
 GPU 0:  90.0C 5977859RPM | 252.7M/244.7Mh/s | A:5022 R: 5 HW:0 U:3.41/m I: 4
 GPU 1: 102.0C 100%    | 280.1M/271.8Mh/s | A:5583 R:15 HW:0 U:3.79/m I: 4

Unfortunately the OS refuses to recognize a second card so I'm limited to one card per machine.  I cannot get Centos 6.4 to recognize two cards under lspci and so opengl refuses to seem them as well.  

Code:

$ lspci -nn | grep VGA
0a:00.0 VGA compatible controller [0300]: Advanced Micro Devices [AMD] nee ATI Barts XT [Radeon HD 6800 Series] [1002:6738]

It should look like this:

Code:

$ lspci -nn | grep VGA
06:00.0 VGA compatible controller [0300]: ATI Technologies Inc Barts XT [ATI Radeon HD 6800 Series] [1002:6738]
0e:00.0 VGA compatible controller [0300]: ATI Technologies Inc Barts XT [ATI Radeon HD 6800 Series] [1002:6738]

I realized after some screwing around that my problem was created when I tried to compile the custom fglrx kernel.  I didn't have developement packages and so I had problems from the start.  Here's my solution.

[Viceroy]

What is your hardware / software / driver combination?

(1) PowerColor AX6870x2
Centos 6.3
catalyst 12.3

Does it work as expected?

Strangley cgminer and bfgminer both compile with cgminer even showing the GPU's during the compile phase but when I try to run the program the GPU's do seem unavailable to the mining software.  

I have no idea why this setup doesn't work as it did before the upgrade to Centos 6.4.


later edited to include:
I realized after some screwing around that my problem was created when I tried to compile the custom fglrx kernel.  I didn't have developement packages and so I had problems from the start.  Here's my solution.

[Beaflag VonRathburg]

I had a 6870x2 and a single 6870 in my main desktop a while ago.

Windows 7 x64 Ultimate
Catalyst 11.12
SDK 2.1 and 2.4 (avoids cpu bug)

I dont remember the exact clocks I was using, but I was getting 305 MH / core mining BTC with cgminer. Granted it was the middle of summer (95-100 F) every day, but I had to add an extra slipstream fan to help keep everything cool. You have to use afterburner or trixx to underclock the memory on them. Other than that they work fine.

[briannguyen]

I have 2 x 6870 and they are running okie. One got more heat, I have to put an extra fan.

[Viceroy]

I have 2 x 6870 and they are running okie. One got more heat, I have to put an extra fan.

'scuze my stupidity... what is "okie"?  Is that CEntOS 5?  What Subversion?

Are these 2 x 6870x2's?  Or are these 2 6870's?

Did you need a dongle?  
Did you need two monitors? Can you light two monitors up?

later edited to include:
I realized after some screwing around that my problem was created when I tried to compile the custom fglrx kernel.  I didn't have developement packages and so I had problems from the start.  Here's my solution.

I can deal with multiple GPU's and I'm going to test other versions of CEntOS now to see if I can't get multiple cards working.  Something happened in Centos 6.4 that causes the second video card to not be seen.  I think what happens is all the GPU's of the same type get bundled together but when that happens I can't address them with the mining software.

[gnarcoinguy]

I've got the same questions as Viceroy.  What's your xorg.conf look like?  I can't get two GPUs to work in linux for the life of me.  One works fine, but no matter waht I do I can't get the second one to function properly.... it shows up fine in lspci and aticonfig, but I ust can't use it.

[Viceroy]

I've got the same questions as Viceroy.  What's your xorg.conf look like?  I can't get two GPUs to work in linux for the life of me.  One works fine, but no matter waht I do I can't get the second one to function properly.... it shows up fine in lspci and aticonfig, but I ust can't use it.

Answered in this thread: 
https://bitcointalk.org/index.php?topic=170516.msg1805209#msg1805209

[ar9]

I have 2 x 6870 and they are running okie. One got more heat, I have to put an extra fan.

What is an "okie"?

[eroxors]

okie = "okay"