Evaluation of UPC on the Cray X1
Tarek A. El-Ghazawi, François Cantonnet, Yiyi Yao, Jeffrey S. Vetter · 2005
ABSTRACT: UPC is parallel programming language which enables programmers to expose parallelism and data locality in applications with an efficient syntax. Recently, UPC has been gaining attention from vendors and users as an alternative programming model for distributed memory applications. Therefore, it is important to understand how such a potentially powerful language interacts with one of today’s most powerful, contemporary architectures: the Cray X1. In this paper, we evaluate UPC on the Cray X1 and examine how the compiler exploits the important features of this architecture including the use of the vector processors and multi-streaming. Our experimental results on several benchmarks, such as STREAM, RandomAccess, and selected workloads from the NAS Parallel Benchmark suite, show that UPC can provide a high-performance, scalable programming model, and we show users how to leverage the power of X1 for their applications. However, we have also identified areas where compiler analysis can be more aggressive and potential performance caveats.