Apple Inc.
Performance-based graphics processing unit power management

Abstract:

Performance counters provided in a graphics processor unit (GPU) are used to provide values used to make a determination of GPU activity so that power management can be exercised. In preferred embodiments counter values relating to computation unit idle times, computation unit stall times, DRAM bandwidth and computation unit stall times due to a sampler wait are utilized to determine performance level. If performance is above a minimum level but the GPU is above certain idleness determinations provided by those values, the GPU can have portions powered down to reduce power consumption while not having a noticeable effect on operations. Based on the various counter values, portions of the GPU can be turned off or disabled to reduce power consumption without having a noticeable effect on perceived GPU performance.