AMD Dual-Core Linux Cluster deplyed at University of California.

well it is not at berkeley but at Davis. The University of California at Davis is an early InfiniPath customer and represents the very first AMD dual-core Opteron cluster deployed with PathScale InfiniPath.
Pathscale announcement was made at LinuxWorld in San Francisco.
The ultra-low latency and unprecedented messaging rate of the PathScale InfiniPath HTX Adapter greatly improves MPI application performance and Linux cluster utilization, enabling scientists, mathematicians and engineers to solve new problems with higher degrees of resolution than ever before. The highly pipelined, cut-thru design of InfiniPath is optimized for applications sensitive to communication latency, the most difficult problem to overcome when migrating from large SMP systems to clusters. InfiniPath delivers superior Interconnect performance at commodity price levels by implementing a high-performance software stack and connecting directly to the AMD Opteron™ processor via a standard HyperTransport HTX slot. When combined with low-latency InfiniBand switching from Cisco (TopSpin), Silverstorm (Infinicon) or Voltaire, InfiniPath enables applications to reliably scale to hundreds or thousands of nodes.
The Center for Computational Science and Engineering (CSE) at the University of California, Davis is concerned with the development of computational models and simulations as a means of understanding complex physical and biological processes, and to model and visualize entirely abstract processes encountered in physics, mathematics, engineering and computer science.
The Center for Computational Science and Engineering (CSE) at the University of California, Davis. was among the first to adopt the PathScale InfiniPath interconnect . CSE is implementing a 144-CPU AMD Opteron processor-based Linux cluster that leverages InfiniPath to run computational models and simulations related to physics, mathematics, engineering, biomedical diagnostics, and other processor-intensive HPC applications. This deployment consists of 36 server nodes from TeamHPC, a division of M&A Technology. Each server is equipped with two dual-core AMD Opteron processors and an InfiniPath HTX InfiniBand Adapter. They are interconnected with a Cisco TopSpin 270 InfiniBand switch.
The CSE also uses The PathScale EKOPath Compiler Suite at the facility.