As shown in Figure 3, the execution time of the CPU is much longer than that of the GPU. In general, the GPU processes a large amount of operations more efficiently than the CPU, because the many-core based GPU is optimized for parallel processing. Especially, mathematical or scientific applications can get high performance by utilizing the many-core GPU. Since the executed benchmark applications (SAD, CP, TPACF, MM) require parallel operations for high performance, the GPU can process the operations more efficiently than the CPU. As shown in Figure 4, energy consumption is also reduced significantly when the application is executed on the GPU compared to the CPU. In this evaluation, energy efficiency is mainly determined by the execution time. Figure 5 shows the temperature of two processing units. In the graph, CPU temperature goes higher when the application is executed on the CPU than the GPU. GPU temperature also goes higher when the application is executed on the GPU than the CPU, since the temperature goes up as more resources are utilized. Temperature is a very important factor in
determining the system efficiency, because high temperature in the processor causes negative impact on reliability, lifetime, and performance[4][5][6]. The error rates of electronic devices
increase exponentially as the temperature goes up[18][19]. Moreover, the lifetime of the processor is reduced by half if the temperature increases by about 10~15