关键词: 图形处理器（GPU）, 第一性原理, 平面波贋势密度泛函

Abstract: First principle calculation based on plane wave is the most popular method in material science simulation. However, traditional CPU parallelization has encountered the scalability bottleneck. Thus the absolute computing time cannot be reduced by using more CPU cores. This paper presents a first principle calculation software on large scale GPU (graphic processing unit) cluster: Ultra-Mat. It also redesigns and implements the algorithm: (1) Utilize a hybrid parallelization scheme to do FFT (fast Fourier transform) in single GPU card. (2) Design and implement a mix precision algorithm to avoid CPU-GPU memory copy and MPI (message passing interface) communication. (3) Implement more than 90% of the codes using CUDA. This step reduces the CPU-GPU memory copy operation, which is an accepted bottleneck in the heterogonous supercomputer. For a 512 atom GaAs system, the testing results show that, the method of using 256 GPU cards has 18 times speedup in the electronic structure calculation compared with 4096 CPU cores.

Key words: graphic processing unit (GPU), first principle calculation, plane wave pseudopotential density functional theory