CryoCache: A Fast, Large, and Cost-Effective Cache Architecture for Cryogenic Computing

Session: Exotic architectures--Keep architecture weird!

Authors: Dongmoon Min (Seoul National University); Ilkwon Byun (Seoul National University); Gyu-Hyeon Lee (Seoul National University); Seongmin Na (Seoul National University); Jangwoo Kim (Seoul National University)

Cryogenic computing, which is to run a computer at extremely low temperatures (e.g., 77K), is a highly promising solution to dramatically improve the computer's performance and power efficiency thanks to the significantly reduced leakage power and wire resistance. However, computer architects are facing fundamental challenges in developing and deploying cryogenic-optimal architectural units due to the lack of understanding about its cost-effectiveness and feasibility (e.g., device and cooling costs vs. speedup, energy and area saving) and thus how to architect such cryogenic-optimal units. In this paper, we propose CryoCache, a cost-effective, technology-feasible cryogenic-optimal cache architecture running at 77K. For this goal, we first thoroughly analyze the cost-effectiveness and feasibility of various on-chip memory cell technologies running at 77K. Based on the analysis, we architect cryogenic-optimal caches with conventional technology-feasible 6T-SRAM and 3T-eDRAM cells whose performance, area, and power benefits at 77K clearly outweigh their cooling costs. Our evaluations show that our example CryoCache architecture achieves 2 times faster cache access and 2 times larger capacity compared to conventional caches running at the room temperature. To the best of our knowledge, this is the first work to propose a fast, large, and cost-effective cache architecture which can be applied to cryogenic computing.