clDXTCompression example not working, different errors with CPU and GPU

Discussion created by ri239 on Jan 12, 2010
Latest reply on Jan 13, 2010 by ri239

Just trying the AMD SDK on a Radeon 5870, and unfortunately I'm running into some really weird issues with an example from the NVIDIA SDK (clDXTCompression.)

First of all, I added #pragma OPENCL EXTENSION cl_khr_byte_addressable_store : enable to get it compiled properly with the AMD Stream SDK (I'm using the ATI Stream SDK v2.0 on Vista/x64.) I also had to follow the instructions at http://developer.amd.com/support/KnowledgeBase/Lists/KnowledgeBase/DispForm.aspx?ID=71 to obtain a proper context for running OpenCL.

Now the app successfully runs (i.e. produces no errors), but the output is completely broken -- even worse, the output is different when running the CPU and the GPU version. Any ideas where to start debugging? The GPU version fills the complete output buffer, but the ordering is totally off ... seems like random noise going on.

So, the questions are:

  • Is cl_khr_byte_addressable_store going to be ever supported on the HD5870? Right now, it requires you to enable the extension using #pragma, but does not fail afterwards even though the extension is not supported (?)
  • Where should I start for CPU debugging?