It's worth mentioning that while HSA specifically may or may not have lived up to its "hype", it did succeed in being on of the first technologies (to my knowle

It's worth mentioning that while HSA specifically may or may not have lived up to its "hype", it did succeed in being on of the first technologies (to my knowledge) to provide hardware support for cache-coherent memory between processing elements. This is an important concept to parallel computing because there is significant latency involved in transferring data between CPU and GPU RAM. HSA backs OpenCL 2.0's SVM (Shared Virtual Memory) and CUDA 6's Unified Memory with actual hardware, making these APIs more than convenient software abstractions. Hardware unified memory opens up a whole new set of algorithms to GPU-parallelization by removing the memory transfer latency barrier.