[CoolGuySteve]

AMD and Apple tried to push OpenCL but the design of it, a C-like kernel compiled to the GPU with LLVM and managed by the Khronos consortium, tended to lag in absolute performance to CUDA which was able to take advantage of evolutions in GPU design more closely.

Nowadays almost nobody cares about OpenCL.

[jjoonathan]

The feature lag wasn't the problem, the bugs were the problem: the only reliable OpenCL implementation was the one from Nvidia, but this meant it tended to drive people towards Nvidia rather than steal them away.

[pjmlp]

Also apparently the reason behind Apple's cut with Khronos seems to be related to how OpenCL was managed by them.

[talldayo]

"Hey Khronos, can we tweak the OpenCL spec to be even more restrictive and higher-level, then rebrand it under our proprietary 'Metal' architecture so we can license it out to our competitors?"

"...no, but you could expand on OpenCL or Vulkan compute if you wanted. There are other spec stakeholders, we can't give you carte-blanche control, Apple."

"Why do you insist upon mismanaging the industry's APIs? Screw you guys!" <Beginning of mid 2010s "Khronos Drought" at Apple Computers>