All the malfunctioning OpenCL code I&#x27;ve ever seen is because they were former CUDA users and simply didn&#x27;t know how to properly use OpenCL (a common example, they use a workgroup size of less than 64 (aka a warp or a wavefront), which is also unoptimized on modern Nvidia hardware too).<p>And as I said above, there is no performance difference between OpenCL and CUDA on Nvidia hardware; although, I should probably amend that with &quot;as long as both versions of the code are sane.&quot;