ZU1: An Efficient Early Zrange Test Unit

摘要

GPU has been applied to more and more visions which demand the hardware with higher performance, faster speed and lower computational cost. We propose a novel early z architecture named ZU1 who locates prior to the pixel shader stage for z range test. The module treats 8x8 pixel patch called tile as an input entry to calculate the tile’s z range, meanwhile acquiring cache zrange from z cache to which the tile zrange compares against according to the compare mode, so as to fastly evaluate z test for accepting or rejecting the tile. We benchmark our design on 3DMark set demonstrate substantial gains with 40% reject ratio and thousands of workloads per frame saving.