Energy Efficient Dim and Dark Cache for Temperature Reduction of Chip Multiprocessors

Abstract

Background: For high computation, parallel and distributed processing chip multiprocessors are widely used. In chip multiprocessors, large on chip cache memories are used for performance improvement and speedy execution of the task. These cache memories consume 13% to 45% of the overall power consumed by the entire chip. As chip size shrinks with technology scaling, static energy consumed by the chip increases. This results in heating and chip malfunctioning. To solve this problem we apply static energy reduction techniques to Last Level Cache (LLC) to reduce static energy consumption and thereby chip temperature rise. Methods: Static energy reduction is achieved with two methods. DIM_OLY_SEL Policy:- In this policy, static Energy Reduction is achieved by dimming cache banks. DIM_DARK_PAT Policy:- In this method, dimming as well as darkening techniques are used to save static energy and thereby, temperature reduction. Results: With the implementation of DIM_OLY_SEL policy LLC, Temperature Reduction up to 1.4 Kelvin, improvements in EDP (Energy Delay Product) gains up to 28% and leakage energy Saving up to 23% is observed. With the implementation of DIM_DARK_PAT, we observed LLC temperature reduction up to 4.7 Kelvin, EDP gain improvement of 33 % and leakage energy saving 23%. Conclusion: DIM_OLY_SEL and DIM_DARK_PAT Policies are observed to be very effective policies for energy saving and chip temperature reduction. Hence, they can be used effectively for safe chip multiprocessor functioning.