Hauptnavigation

• News
• About Us
• Our services
• High Performance Computing at Aachen University
• Virtual Reality
• Events
• ServiceDesk

Inhalt

The Sun HPC Cluster at the RWTH Aachen University

October 2009. 200 nodes of the new Nehalem Cluster are put into operation. more...

March 2009, Parallel Programming in Computational Engineering and Science (PPCES, formerly SunHPC Event)

The future high performance computing system of the RWTH Aachen University will be provided again by Sun Microsystems!

A compute power of more than 200 TeraFlop/s will be installed by end of 2010! Once the building is completed ...

March 2008, SunHPC 2008 -Joint SunHPC and VI-HPS Workshop

October 2005. Four Dual-Core Quad-Opteron Sun Fire V40z installed

April 2005. Over 2 TeraFlop/s Linpack Performance

After upgrading from UltraSPARC III to UltraSPARC IV we ran the Linpack benchmark on the 20 biggest of our UltraSPARC IV-based compute servers and achieved 67% of the theoretical peak performance. A linear system with 499,200 unknowns was solved in 11:12:48.8 hours at an average speed of 2054.4 billion floating point operations per second (GFlop/s). The program had a total memory footprint of 2 Terabyte. The 20 compute nodes are equipped with 672 dual core UltraSPARC IV processors running at 1050 or 1200 MHz clock speed. 1276 processor cores were kept busy with 82,930,000,000 million floating point operations leaving 68 cores free for networking and system tasks.

The following components contributed to this unexpected good result:

• the Sun Performance Library, a highly tuned mathematical library, was employed to squeeze out every machine cycle when multiplying matrices
• the extremely fast Sun Fire Link network together with
• the fast and thread-safe implementation of the message passing interface (MPI), which is part of Sun HPC ClusterTools and
• facilitated a very smart hybrid (MPI+OpenMP) implementation of the linear equation solver by Eugene Loh (Sun).
• The different clock speeds of the available UltraSPARC IV processors where adjusted with a simple thread balancing technique (see below).

In Aachen four Sun Fire E25K nodes and two groups of 8 Sun Fire E6900 nodes each are connected with the extremely fast Sun Fire Link network. Gigabit Ethernet is used to connect these three Fire Link groups.

The Algorithm. The cluster Linpack implementation used macro dataflow techniques to maximize concurrency. Such techniques are used today by the Sun Performance Library to deliver optimal scalability for dense linear algebra routines on shared-memory systems.

Thread Balancing. In order to fill the performance gap between the slower clock rate of the 72 dual core processors of the Sun Fire E25K nodes (1050 MHz) versus the clock rate of the 24 dual core processors of the Sun Fire E6900 nodes (1200MHz) we used a thread balancing technique. We started 2 MPI processes with 23 threads on each of the 16 Sun Fire E6900 nodes and 5 MPI processes with 27 threads on each of the four Sun Fire 25K nodes.

September 2004. Sun Fire SPARC-Cluster upgraded to UltraSPARC IV. All Sun Fire 15K and Sun Fire 6800 nodes have been upgraded to UltraSPARC IV this month. With the new processors they obtain new model names: Sun Fire E25K and Sun Fire E6900. Together with 8 Sun Fire E2900 nodes, which have been installed in July, we are now running 768 UltraSPARC IV processors in the cluster. As these processors contain two CPU cores each, the programmer has an impression of having 1536 CPUs available.

March 2003. Sun Fire Link Network installed. The low latency - high bandwidth Sun Fire Link networks have been installed to tightly link together 2 groups of 8 Sun Fire 6800 systems and one group consisting of the 4 Sun Fire 15K systems. With this configuration we obtained the rank 151 of the top500 list of the fastest computers with respect to solving large linear equations in November 2003. A system of over 200,000 unkowns was solved running at 891,4 GFlop/s.