Animal Logic has the only supercomputer in Australia to make the latest top 500 list but the 4096-core HP cluster dropped 134 spots in the past six months.
The computer, an HP cluster platform 3000 BL 2x220 [PDF], came in at position 279 achieving 21905 Gigaflops per second.
It was ranked 145 in the November 2008 report.
The United States continues to dominate the supercomputer space with 58 per cent of the top 500 machines residing there.
The UK (44 machines), Germany (29), France (23) and China (21) round out the top five supercomputing nations respectively.
The U.S. Department of Energy maintained the top two spots with the roadrunner system at the Los Alamos National Laboratory achieving 1.105 petaflops per second, and the Cray XT5 Jaguar system at the Oak Ridge National Laboratory reaching 1.059 petaflops per second.
Germany was the only country to have machines in the top 10 other than the United States.
Both are installed at the Forschungszentrum Juelich (FZJ) research organisation in Germany.
JUGENE, a new IBM BlueGene/P system, ranked third in the world, achieving 825.5 teraflops per second with a theoretical peak performance of just above one petaflop per second.
Its sister, JUROPA, built from Bull Novascale and Sun SunBlade x6048 servers, ranked tenth in the world.
The presence of supercomputers in China and Saudi Arabia also drew special attention.
The King Abdullah University of Science and Technology (KAUST) in Saudi Arabia is home to a brand new player, an IBM BlueGene/P system which ranked 14th in the world.
Microsoft will undoubtedly be pleased that the Chinese-built Dawning 5000A at the Shanghai Supercomputer Center ranked at number 15.
It is the largest system which can be operated with the Windows HPC 2008 operating system, according to top500.org.
Australia has fallen behind in the top500 list in recent years. It has held double-digit spots in the list on only two occasions since 1993 - 10 computers ranked in that year, and 11 in 2005.
It has also had a machine rank as high as 26th in the world in 2005 - an SGI Altix system at the Australian Partnership for Advanced Computing in Canberra.
That machine achieved 8974 Gigaflops per second in the top500 benchmarks. The entry level for the latest list is 17.1 Teraflops per second, highlighting the speed changes in the industry in recent years.
In other trends to emerge from the list, quad-core processors are found in 383 systems, 102 systems are using dual-core processors, and only four systems still use single core processors.
Intel also continues to dominate machines. Almost 80 per cent of the top 500 - some 399 machines - now use Intel processors, and the chip maker appear to be wrestling market share away from the other players.
IBM Power processors are the second most commonly used processor family with 55 systems, although this is slightly down from six months ago.
AMD's Opteron family powers 43 systems, down from 59.