A Case Study of Energy Efficiency on a Heterogeneous Multi-Processor

In this extended abstract, we present a case study of powerefficiency on a heterogeneous multi-core processor, Exynos 5422 based on the ARM big.LITTLE architecture. We show the effect of thermal management on the big (faster) cores and the comparisons between big and LITTLE (slower) cores using the EEMBC CoreMark-Pro benchmarks. As expected, the LITTLE cores are more energy efficient than the big cores at the maximum performances of both cores for all workloads.

However, the big cores are similarly or more power efficient as LITTLE cores for 5 out of 9 workloads when the performance of both cores are matched by lowering the clock frequency of big cores. Delay-insertion for matching the performance is only effective for one workload, but it may be useful in a multi-programmed environment when the frequency of each core cannot be set independently (which is the case for Exynos).