Using affinity masks to control multi-GPU processing

One embodiment of the present invention sets forth a set of application programming interface (API) extensions that enable a software application to control the processing work assigned to each GPU in a multi-GPU system. The software application enumerates a list of available GPUs, sets an affinity mask from the enumerated list of GPUs and generates an affinity device context associated with the affinity mask. The software application can then generate and utilize an affinity rendering context that directs rendering commands to a set of explicitly selected GPUs, thus allocating work among specifically selected GPUs. The software application is empowered to use domain specific knowledge to better optimize the work assigned to each GPU, thus achieving greater overall processing efficiency relative to the prior art techniques.