PC机群上JIAJIA与MPI的比较

对JIAJIA和MPI (message passing interface)是进行了比较.JIAJIA和MPI分别代表共享存储和消息传递的编程模式.MPI显式进行数据传输,编程复杂;JIAJIA由底层维护数据一致性,并附加提供简单的消息传递函数,编程容易、灵活.JIAJIA分配共享内存时开销较大,初始化时间比MPI长.提出了一个关于并行加速比与进程数目之间关系的近似经验公式,推出JIAJIA和MPI性能差距随着进程数目的增多而增大的结论.测试结果表明,大部分应用程序的JIAJIA和MPI版本的并行性能差距不超过10%.对于通信量很小的应用程序,其JIAJIA和MPI的性能差距较小,而通信量本身较大的应用程序,其JIAJIA和MPI的性能差距主要取决于运行时产生的实际通信量.

Comparing JIAJIA with MPI on PC Cluster

JIAJIA and MPI (message passing interface) are compared in this paper. JIAJIA and MPI represent the programming model of share memory and message passing respectively. MPI handles message transmission manually and is hard for programming. JIAJIA maintains data coherence by lower layer and provides simple message passing APIs, so it is easy and flexible to program. It takes more time for JIAJIA to initialize applications than MPI. A rough empirical formula about speedup and machine size is presented in this paper. Experimental results show that both JIAJIA and MPI have good parallel performance on PC clusters and their performance difference of most testing applications is lower than 10 percent. Applications with fewer messages have better performance and the gap between JIAJIA and MPI is minor. While messages increase, parallel performance decreases and the gap between JIAJIA and MPI depends on the amount of messages they produce.