Power consumption is one of the main challenges to achieve Exascale performance. Current research trends aim at overcoming power consumption constraints using low-power processors. Although new processors feature sensors that enable precise power measurements, they provide different interfaces to collect data, making it difficult to correlate performance with energy consumption. To overcome this issue, the authors developed a platform-independent tool that collects power and energy data from homogeneous and heterogeneous systems. Using this tool, they provide a detailed comparison between a low-power processor (ARM big.LITTLE) and a high performance processor (Intel Sandy Bridge-EP) using all applications from the NAS parallel benchmarks and a real-world soil irrigation simulator. The results show that the average power demand of Intel Sandy Bridge-EP is within 12.6× to 152.4× higher than ARM big.LITTLE, whereas its average energy consumption is within 1.6× to 7.1× superior. Overall, ARM big.LITTLE presented a better performance/energy trade-off when it takes <9.2× the execution time of Intel Sandy Bridge-EP to solve the same problem.