I don’t have much expertise with OpenCL compared to CUDA. However, if you have questions about cl_khr_fp16 , a suggestion might be to check if the support is advertised by the driver (of course you should first enable that feature as indicated in the driver release notes.) If it isn’t, then I wouldn’t expect the extension functionality to work. If it is advertised, and you believe that some piece of functionality associated with that extension is not being handled by the NVIDIA OpenCL driver correctly, you could file a bug. You’ll be asked for a repro/test case, most likely. You can also ask OpenCL questions here, but the community here is more focused on CUDA. YMMV. (And, make sure you have a new enough driver for the release note update to apply.)