progressivePhotonMap: OptiX Error: Unknown error (Details: Function "_rtContextCompile" ca

Hi all, I am new to Optix.
I have successfully build everything, and would like to try out the progressivePhotonMap example.
The downloaded pre-complied executable runs fine;
however, the one I build by myself give the following error:

OptiX Error: Unknown error (Details: Function “_rtContextCompile” caught excepti
on: Inconsistent device bitness detected with given input PTX: traverse_geometry
_3, [1573417])

Anyone have any ideas on what is wrong from my build or setting?
Thanks so much in advance if you might help.


Hi, that error usually happens when you’re trying to use 32-bit PTXes with a 64-bit OptiX program. Please check your PTX and OptiX application bitness in order for them to match.

Hi marknv,
Thanks for your reply; however, I am still confused by some points.

  1. How are the PTX generated? by CMake?
  2. In CMake, I have already clicked the checkbox for CUDA_64_BIT_DEVICE_CODE
    Is it not enough for building a 64-bit project?
  3. I double checked the CUDA 5.5 is running on 64-bit as well as Optix is under “Program File” rather than “Program File (x86)” in Windows 8, what else do I needa check? Cg matters?

Thanks in advance for your kindly answer.


See the OptiX 3.0.1 release notes:

“Note that CUDA 5.5 is not supported in this release.”