AMD Dives Deep On Asynchronous Shading

Earlier this month at GDC, AMD introduced their VR technology toolkit, LiquidVR. LiquidVR offers game developers a collection of useful tools and technologies for adding high performance VR to games, including features to make better utilization of multiple GPUs, features to reduce display chain latency, and finally features to reduce rendering latency. Key among the latter features set is support for asynchronous shaders, which is the ability to execute certain shader operations concurrently with other rendering operations, rather than in a traditional serial fashion.

It’s this last item that ended up kicking up a surprisingly deep conversation between myself, AMD’s “Chief Gaming Scientist” Richard Huddy, and other members of AMD’s GDC staff. AMD was keen to show off the performance potential of async shaders, but in the process we reached the realization that to this point AMD hasn’t talked very much about their async execution abilities within the GCN architecture, particularly within a graphics context as opposed to a compute context. While the idea of async shaders is pretty simple – executing shaders concurrently (and yet not in sync with) other operations – it’s a bit less obvious just what the real-world benefits are why this matters. After all, aren’t GPUs already executing a massive number of threads?