OpenCL 2.0 was ignored because implementing shared virtual memory was mandatory, but it simply isn't possible to implement without cache coherence all the way i

OpenCL 2.0 was ignored because implementing shared virtual memory was mandatory, but it simply isn't possible to implement without cache coherence all the way into the GPU memory. Now that Intel has developed their own GPUs, they have gone out of their way to completely ignore SVM and went with their own proprietary USM extension of OpenCL and the Intel driver developers themselves said SVM is difficult to get right. Intel and AMD were the only ones implementing OpenCL 2.0 and the SVM implementation by AMD was basically unusable. OpenCL 3.0 got rid of the mandatory features of OpenCL 2.0 that nobody was willing to implement.