Organizations: Beijing National Research Center for Information Science and Technology Department of Electronic Engineering, Tsinghua University, Beijing 100084, China · School of Electronics and Internet of Things Chongqing Polytechnic University of Electronic Technology, Chongqing 401331, China
Deep neural network (DNN) inference on mobile devices often incurs high latency and energy consumption due to limited computing and memory resources. To enable energy-efficient DNN inference, most existing studies focus on dynamic voltage and frequency scaling (DVFS) for adjusting the computing frequency, while the impact of memory frequency on the inference performance has been greatly overlooked. In this paper, we consider the impact of memory frequency and computing frequency on DNN inference time, and jointly optimize these two frequencies together with communication resources for energy-efficient DNN inference. Based on a realistic inference time model, we formulate an optimization problem to minimize the energy consumption of all mobile devices under the deadline constraint. For local inference, we derive a near-optimal closed-form solution via convex optimization, while an optimal closed-form solution for transmission power is obtained for edge inference with the given bandwidth. Furthermore, we propose a low-complexity heuristic algorithm to effectively solve the overall problem with polynomial time complexity. Simulation results based on measured data show that the proposed near-optimal solution for local inference can achieve optimal performance under strict deadline constraints, with a performance gap of up to 2.5% compared with the optimal solution. Meanwhile, our proposed algorithm significantly reduces the energy consumption of devices by up to 10.4% compared to other methods.
Figures & tables
Fig. 1: Impact of memory frequency scaling on DNN inference time and energy consumption for ResNet152 and VGG19 on Jetson TX1.
Fig. 2: Illustration of an edge intelligence system that jointly optimizes memory and computing frequencies, transmission power and bandwidth.
DNN Model
Mobile Device
fn,mem (GHz)
fn,com (GHz)
an
bn
cn
dn
κn,mem
κn,com
σn
ResNet152
Jetson TX1
[0.102, 1.6]
[0.1536, 0.9984]
0.039
1.552
0.211
0.358
0.152
1.115
2.097
VGG19
0.110
1.296
0.099
0.629
TABLE I: Parameters of DNNs and Devices.
Fig. 3: Comparison for the local energy consumption of optimal and near-optimal solutions under different deadlines.
Fig. 4: Comparison for the memory frequency and computing frequency of optimal and near-optimal solutions under different deadlines.
Fig. 5: Energy consumption under various bandwidth resources and devices.