The Center for Computing and Communication (CCC) at the RWTH Aachen University has recently published details about two interesting clusters they operate using Sun technology.  RWTH Aachen is the largest university of technology in Germany and one of the most renowned technical universities in Europe, with around 28,000 students, more than half of which are in engineering (according to their website).

Check this out!

First, there is a huge Opteron-Linux-Cluster that consists of 64 of Sun's V40z servers, each with four Opteron CPUs. The 256 processors total 1.1TFlop/s (peak) and have a pool of RAM equal to 512GB. Each node runs a 64-bit version of Linux. Hybrid Programs use a combination of MPI and OpenMP, where each MPI process is multi-threaded. The hybrid parallelization approach uses a combination of coarse grained parallelism with MPI and underlying fine-grained parallelism with OpenMP in order to use as many processors efficiently as possible. For shared memory programming, OpenMP is becoming the de facto standard.

See: http://www.rz.rwth-aachen.de/computing/info/linux/primer/opteron_primer_V1.1.pdf

Another Cluster is based on 768 UltraSPARC-IV processors, with an accumulated peak performance of 3.5 TFlop/s and a total main memory capacity of 3 TeraByte. The Operating System's view of each of the two cores of the UltraSPARC IV processors is as if they are separate processors. Therefore from the user's perspective the Sun Fire E25Ks have 144 “processors”, the Sun Fire E6900s have 48 “processors” and the Sun Fire E2900s have 24 “processors” each. All compute nodes also have direct access to all work files via a fast storage area network (SAN) using the QFS file system. High IO bandwidth is achieved by striping multiple RAID systems.

See: http://www.rz.rwth-aachen.de/computing/info/sun/primer/primer_V4.0.pdf