A Thermal Mitigation Algorithm Based on the Power Characteristics of Mobile Application Processors

Abstract

Modern mobile devices suffer from severe power and thermal issues due to the adoption of high-frequency multi-core processors. However, methods of resolving the thermal problems in mobile environments are restricted due to their size, semiconductor process technology, and battery limitations. Mobile devices generally rely on a software framework called the Thermal Management Model (TMM). However, conventional TMMs suffer from inevitable performance degradation due to the thermal response. We propose a new Thermal Mitigation Algorithm (TMA) to optimize performance and thermal mitigation by considering the multi-core power curve of a mobile CPU which is experimentally derived using a typical smartphone and thus resolve this issue. Our proposed scheme aims to reduce thermal problems and enhance system performance by limiting the usage of power-inefficient frequencies when operating on a multi-core. We evaluate the proposed algorithm on a real system using a typical smartphone and conduct the performance measurement using the AnTuTu benchmark v4.5.1. In addition, we use the on-chip temperature sensors of CPU cores and a crystal oscillator embedded in the Application Processor (AP) to monitor the temperature of the mobile device. The result shows that our scheme, respectively reduce the average temperatures of CPU cores and a crystal oscillator by 6.61% and 5.02% while improving system performance by 3.24%. In conclusion, we reduce the thermal problems and enhance performance simultaneously using the proposed TMA.