Standalone GPUs can benefit from HSA, but not to the extent of an APU. A dedicated GPU will have its own attached memory as well as shared memory with the main CPU. Due to the communication latency issues of writing from main memory to the video cards memory, it is not nearly as seamless as what an APU can accomplish. It makes sense that such a setup would benefit a solution with a shared memory pool as well as a shared memory controller. Everything else involves more latency and differing amounts and types of memory."
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