Hi,

I just had an annoying multi-hour debugging session, trying to figure out why cgminer thinks there's only one GPU in my (Debian Testing) system.

$ aticonfig --list-ad
* 0. 06:00.0 ATI Radeon HD 5800 Series
  1. 07:00.0 ATI Radeon HD 5800 Series
  2. 08:00.0 ATI Radeon HD 5450

Turns out that AMD is being stupid. Again.

OpenCL 1.1 AMD-APP-SDK-v2.4 (595.10) (don't remember where I downloaded it from): library works.
OpenCL 1.2 AMD-APP (831.4) (available from http://developer.amd.com/sdks/AMDAPPSDK/Pages/default.aspx ) does NOT see more than one GPU.

You can extract the build number etc. from the library with
$ strings -a /pth/to/the/library.so | grep "^OpenCL.*AMD-APP"
 
Sorry if this has been mentioned before, but this thread is too long to scan everything.