Comparing the Scalability of the Cray T3E-600 and the Cray Origin 2000 Using SHMEM Routines

This paper presents relative scalability results for the Cray T3E-600 and the Cray Origin 2000 on ve communication tests for a variety of message sizes and for 4, 8, 12, ..., 128 processors. The ve communication tests were chosen to represent commonly-used communication patterns with low contention (accessing distant messages, a right shift and a binary tree broadcast) to communication patterns with high contention (a \basic" broadcast and an all-to-all). Both machines scaled roughly the same on all tests except the right shift with short messages where the T3E scaled signiicantly better than the Origin. However, it should be noted that the T3E outperformed the Origin 2000 for most of these tests.