  Training deep neural networks (DNNs) is a major workload in datacenters
today, resulting in a tremendously fast growth of energy consumption. It is
important to reduce the energy consumption while completing the DL training
jobs early in data centers. In this paper, we propose PowerFlow, a GPU clusters
scheduler that reduces the average Job Completion Time (JCT) under an energy
budget. We first present performance models for DL training jobs to predict the
throughput and energy consumption performance with different configurations.
Based on the performance models, PowerFlow dynamically allocates GPUs and
adjusts the GPU-level or job-level configurations of DL training jobs.
PowerFlow applies network packing and buddy allocation to job placement, thus
avoiding extra energy consumed by cluster fragmentations. Evaluation results
show that under the same energy consumption, PowerFlow improves the average JCT
by 1.57 - 3.39 x at most, compared to competitive baselines.
