Adding a separate queue for async compute
In this section, we are going to illustrate how to use separate queues for graphics and compute work to make full use of our GPU. Modern GPUs have many generic compute units that can be used both for graphics and compute work. Depending on the workload for a given frame (shader complexity, screen resolution, dependencies between rendering passes, and so on), it’s possible that the GPU might not be fully utilized.
Moving some of the computation done on the CPU to the GPU using compute shaders can increase performance and lead to better GPU utilization. This is possible because the GPU scheduler can determine if any of the compute units are idle and assign work to them to overlap existing work:
Figure 5.3 – Top: graphics workload is not fully utilizing the GPU; Bottom: compute workload can take advantage of unused resources for optimal GPU utilization
