Early Evaluation of the Cray XT3 at ORNL

Oak Ridge National Laboratory recently received delivery of a Cray XT3. The XT3 is Cray’s third-generation massively parallel processing system. The system builds on a single processor node—the AMD Opteron—and uses a custom chip—called SeaStar—to provide interprocessor communication. In addition, the system uses a lightweight operating system on the compute nodes. This paper describes our initial experiences with the system, including micro-benchmark, kernel, and application benchmark results. In particular, we provide performance results for important Department of Energy applications areas including climate and fusion. We demonstrate experiments on the partially installed system, scaling applications up to 3,600 processors.