Apple cluster third in new supercomputer ranking

A computer cluster consisting of 1,100 Apple Computer Inc. Power Mac G5 desktops that were purchased online and connected together in a matter of weeks by Virginia Polytechnic Institute and State University is currently the third fastest computer in the world, according to the latest edition of the closely followed Top 500 ranking, which was published Sunday.

The cluster, which attracted considerable attention when it was announced earlier this year because of its use of off-the-shelf computers and networking technology, is the highest new entry in the twice-yearly ranking that also includes a number of other new machines based on clusters of standard computers running the Linux operating system.

The ranking relies on computer owners or makers submitting details of their machines and is based on the results of a standard benchmark called Linpack. Machines are ranked by the maximum number of floating operations per second (flops) achieved during the test.

Top two positions in the latest edition of the list are unchanged with the NEC Corp.-built Earth Simulator of the Japan Marine Science and Technology Center ranked number one at 35.9T flops (gigaflops) and the Hewlett-Packard Co.-built ASCI-Q machine at Los Alamos National Laboratory ranked number two at 13.9T flops.

Virginia Polytechnic's Apple cluster gained third place with a 10.3T flops ranking and in doing so also became only the third computer in the world to achieve a performance of more than 10T flops, according to the list compilers. Each node on the cluster is a Power Mac computer with dual 2.0GHz PowerPC 970 processors made by IBM Corp., 4G bytes of memory and 160G bytes of storage. They are connected together using Infiniband interconnect technology and Gigabit Ethernet switches.

Its not just the Apple machine that is making an impact on the ranking. In the six months that have passed since the last ranking, an additional three machines based on clusters of smaller computers, all of which run the Linux operating system, have been deployed that are powerful enough to take positions in the top ten.

A cluster of Dell Corp. PowerEdge 1750 servers with a total of 2,500 Intel Corp. Xeon 3.06GHz processors and running a Red Hat Inc. distribution of Linux ranked fourth. The machine, which is at the National Center for Supercomputing Applications (NCSA) at the University of Illinois at Urbana-Champaign, achieved a maximum performance of 9.8T flops.

Pacific Northwest National Laboratory's MPP2 computer was the fifth-ranked machine with a maximum performance of 8.6T flops. The computer consists of Hewlett-Packard Co. Integrity RX2600 computers and includes a total of 1,936 of the 1.5GHz version of Intel's Itanium 2 chip and also runs a Red Hat version of Linux.

The final new entry into the top ten, at position six, is the Lightning cluster at Los Alamos National Laboratory (LANL). The computer is the fastest system in the ranking based on Advanced Micro Devices Inc.'s Opteron processor and also the first machine to enter the top 10 based on the chip. It includes 2,816 of the processors and achieved a maximum performance of 8.1T flops, according to the ranking. The computer was supplied by Linux Networx Inc.

With these new machines and others, there are now 208 computer clusters in the Top 500, up from 149 in the previous study six months earlier, said the list compilers.

The latest list also marks the emergence of China and Chinese computer makers as growing supercomputing powers.

Deepcomp 6800, a machine based on 1,024 of Intel's Itanium 2 processors running at 1.3GHz, built by the country's Legend Group Ltd., has been ranked the 14th most powerful computer in the world at 4.1T flops. It also puts China, in terms of the maximum performance of a single machine, ahead of all other nations except the U.S. and Japan. The computer is installed at the Chinese Academy of Science (CAS), according to the ranking.

The previous most powerful computer in China, Deepcomp 1800, also installed at CAS, ranked 82 in the new list and has achieved a maximum performance of 1.3T flops.

The 22nd edition of the Top 500 list was released to coincide with the SC2003 Conference in Phoenix, Arizona, which started on Saturday and continues until Friday, Nov. 21. It can be found online at http://www.top500.org .