Abstract:

In this paper, the authors present a library, named Sapporo, which closely emulates the GRAPE-6 API. The library is written in CUDA and implements most common functions that are used in N-body codes supporting GRAPE-6. As a result such codes will be able to use Sapporo without modification to their source code. The library also supports use of multiple GPUs per host. The authors carried out a series systematic tests to test the performance, accuracy and ability of the library to handle a realistic N-body problem. They found the performance of the library with a single G80/G92 GPU is a factor of two higher than that of GRAPE-6A(BLX) PCI(X)-cards, and the sustained performance with 2x GeForce 9800GX2 cards is on par with a 32-chip GRAPE-6 system (about 800 GFlop/s). The accuracy of the library is comparable to that of GRAPE-6 hardware, and its ability to correctly solve a realistic N-body problem provides an alternative for GRAPE-6 special purpose hardware.

(Evghenii Gaburov, Stefan Harfst and Simon Portegies Zwart, SAPPORO: A way to turn your graphics cards into a GRAPE-6, Submitted to New Astronomy)