PEST:由PYNQ集群实现的高能效NEST类脑仿真器

PEST:Energy-Efficient NEST Brain-Like Simulator Implemented by PYNQ Cluster

高性能且低功耗地进行大规模类脑仿真是类脑计算所需解决的最具挑战的问题之一。目前类脑计算的实现方式主要分为硬件实现和软件实现两种。通过硬件实现的专用类脑计算芯片与系统可以提供更佳的能效指标,但代价高、适应性差;基于软件方式的仿真(如NEST)拥有完整的应用生态,可用性好但存在计算速度慢的问题。如果将两种实现方式相结合,通过软硬件协同设计,可以在保证良好应用生态的同时获得更高的计算能效,提出了一种基于FPGA异构平台PYNQ集群的NEST类脑仿真器的高能效实现(PEST)。通过构建大规模PYNQ集群,设计软硬件数据交互接口实现基于NEST仿真器的规模可伸缩类脑计算系统,针对IAF神经元进行FPGA硬件电路设计,利用MPI分布式计算等方式提升了NEST计算效率。实验结果表明:针对不同的计算模型,在PYNQ集群最佳适配情况下,PEST上神经元更新部分的性能相比AMD 3600X提升超过4.6倍,相比Xeon 2620提升超过7.5倍;PEST的更新能效比相比3600X提升超过5.3倍,相比Xeon 2620提升超过7.9倍。

Large-scale brain-like simulation with high performance and low power consumption is one of the most challenging problems in brain-like computing. At present, the implementation of brain-like computing is mainly divided into hardware implementation and software implementation. Dedicated brain-like computing chips and systems implemented by hardware can provide better energy efficiency indicators, but they are costly and poorly adaptable.Software-based simulation(such as NEST)has good availability but has the problem of slow computing speed. If the two implementation methods are combined, through the software and hardware co-design, to ensure a good application ecology while obtaining higher computing energy efficiency, this paper proposes a high-energy-efficiency implementation(PEST)of the NEST brain-like simulator based on the FPGA heterogeneous platform PYNQ cluster. By building a large-scale PYNQ cluster, it designs software and hardware data interaction interfaces to realize a scalable brain-like computing system based on the NEST simulator, designs FPGA hardware circuits for IAF neurons, and uses MPI distributed computing to improve NEST computing efficiency. The experimental results show that, for different computing models, under the optimal adaptation of PYNQ cluster, the performance of the neuron update part on PEST is improved by more than 4.6 times compared with AMD 3600 X, and by more than 7.5 times compared with Xeon 2620. PEST.s updated energy efficiency is more than 5.3 times higher than that of 3600 X and 7.9 times higher than that of Xeon 2620.