Demand-driven register file for multithreaded mobile GPUs

Abstract

Mobile GPUs are used in modern portable devices to satisfy the growing requirements of 3D applications. These GPUs generally integrate hardware multithreaded shaders to improve the throughput for real-time rendering, but they depend on duplicate register files to maintain the context of each hardware thread. This work develops a demand-driven register file (DDRF) to reduce the power consumption by register files. The proposed DDRF is shared on demand among concurrent threads and turns off almost all unused registers. Experimental results reveal the DDRF uses 85.8% less power than a conventional multithreaded GPU. The chip area and circuit latency of DDRF are also discussed.