Sunday, January 22, 2017

Fine grained memory management on AMD Vega GPUs


Recently, some advancements of the upcoming AMD Vega GPU architecture had been disclosed. One of the most interesting features as you might have noticed was the new memory architecture. The upcoming Vega GPUs are reportedly having support for fine grained memory management and employ fast HBM2 memories. In addition, the GPU employs a mechanism which AMD calls high bandwidth cache controller and the GPU memory is referred to as high bandwidth cache. In this sense they claim that it is used as a cache memory, that is a secondary level of cache by having the main system memory serving as the last level of the hierarchy. This fact makes me think that the Vega architecture might support the same fine grained shared virtual memory infrastructure that the NVidia Pascal already implements on its GP100 GPU but that is not clear yet. No reference to shared virtual memory was made so this is just a personal speculation. Only the fact that the GPU would be able to utilize the system memory does not imply that the GPU will utilize the same virtual addressing mechanism as the CPU does. However, it is reasonable to think this will be supported since AMD wants to grab a significant portion of the HPC market through its ROCm platform.

If this is the case then it will prove to be an exciting feature with the benefits I had referred to in a previous post of mine.




Source: Anandtech