On the delay-differential equations x′(t) + a(t)f(x(t − r(t))) = 0 and x″(t) + a(t)f(x(t − r(t))) = 0

Comparison of Cray XT 3 and XT 4 Scalability ∗

The Cray XT3 and XT4 have similar architectures, differing primarily in memory performance and in bandwidth between the node and interconnect. This paper evaluates and compares the scalability of the XT3 and XT4. Kernel benchmarks are used to verify and to quantify the performance differences between the systems. Application benchmarks are used to examine the impact of these differences on scal...

Robotino® XT

The Cray XT Compilers

The Cray XT3 and Cray XT4 supports compilers from the Portland Group, PathScale, and the GNU Compiler Collection. The goal of the paper is to provide Cray XT users with an overview of the different compilers available in the Cray XT Programming Environment. Discussion will highlight the feature and performance differences between the compilers and provide guidelines in determining which compiler

GPFS on a Cray XT

The NERSC Global File System (NGF) is a center-wide production file system at NERSC based on IBM’s GPFS. In this paper we will give an overview of GPFS and the NGF architecture. This will include a comparison of features and capabilities between GPFS and Lustre. We will discuss integrating GPFS with a Cray XT system. This configuration relies heavily on Cray DVS. We will describe DVS and discus...

Debugging Scalable Applications on the XT

Debugging at large scale on the Cray XT can involve a combination of interactive and non-interactive debugging; the paper will review subset attach and provide some recommendations for interactive debugging at large scale, and will introduce the TVScript feature of TotalView which provides for noninteractive debugging. Because many users of Cray XT systems are not physically co-located with the...