The future face of computing

Professor Tony Williams with a sandwich board; worth $80,000 less than ten years ago, but now obsolete.
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Professor Tony Williams inspects the Perseus computer.
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Wednesday, 30 May 2001

The realm of the truly personal computer, only a few decades old, has constantly changed. Now it may be ending.

"We are moving into a future where computers across the globe, from desktop PCs to supercomputers, will be networked together," claims Associate Professor Tony Williams, Deputy Director of Adelaide University's Centre for the Subatomic Structure of Matter. "Linked like that, they can work to full capacity even while in screen-saver mode. This 'computational grid' is the future of large-scale computing and is becoming reality even now," he says.

It is a radical shift in the technology of desktop computing, but it seems inevitable. The huge increases in computing power that make personal computers rapidly obsolete as new models arrive has so far depended on making smaller chips that do more. In the end, one runs up against limitations dictated by the very structure of matter.

"Modern computer chip technology is reaching some fundamental physical limits," said Professor Williams. "The size of the atom limits how many functioning transistors we can fit on a computer chip, and the speed of light limits how big we can make each chip," he said. "Another limitation arises from the need to dissipate heat from these computer chips so that they don't fail due to excessive thermal noise."

The answer appears to be to link computers in parallel. Not only can that provide almost unlimited computing power, it allows a kind of information processing that can't be achieved in any other way.

There are two extremes of this parallelism. In 'loose' parallelism, the network connection between computers (or nodes as they are sometimes called) is relatively slow, such as a standard internet or everyday modem connection. This kind of parallelism is already being used in the SETI@Home experiment, where anybody on Earth with access to a personal computer can take part in the search for extraterrestrial intelligence by processing data from radio telescopes that look for signals of intelligent life on other planets (see http://setiathome.ssl.berkeley.edu/).

More than 3,000,000 computers from around the world are currently cooperating on this search and, through it, more than 1,000 years of single-computer CPU time is being delivered to the SETI program each day.

"There are millions of computers connected to the Internet. Most of them are PCs or work stations sitting on people's desks, and much of the time they are in screen saver mode, or not doing anything." said Dr Paul Coddington, from the University's Department of Computer Science. "Around 3 million people have downloaded the software from the SETI@Home program onto their PCs, and tens of thousands of PCs are running the program at any time. That's a lot of free computer power!"

Professor Williams cautions that "Only certain types of large-scale computing problems can be attacked in this way, such as those where slow communication between the nodes is unimportant."

The other extreme of parallelism is the very 'tight' kind, where nodes are connected by very fast networking to form a parallel supercomputer. A local example of this is the Orion supercomputer used extensively by researchers at the Centre for the Subatomic Structure of Matter. Orion has 40 Sun Microsystem computers, each with 4 central processing units (CPU's), which are connected by very fast Myrinet networking.

The resulting Orion supercomputer was the fastest in Australia when it was installed in 2000, and is currently the third fastest in Australia. Another local and more economical version, using standard fast ethernet networking, is the Perseus cluster consisting of 116 dual-processor Pentium PCs.

"When commissioned, this was the largest PC cluster in Australia and one of the largest in the world," said Professor Williams, "However, because of the slower networking, Perseus cannot attack the same breadth of problems that Orion can."

The rate of change in the power of modern computers is impressive, but demand for computer power for large scale applications is insatiable. "Computers linked in parallel are already being recognized as the fastest and most economical way forward," claims Professor Williams. "The 'computational grid' is a very flexible tool which can link the idle PC on your desk to some of the fastest and most affordable supercomputers in the world," he says.

Supercomputers are also finding many applications outside the disciplines where they were born. They are proving invaluable in fields as diverse as aerodynamics (aeroplane design), fluid flow (ship and boat design), water resource and salinity management, water and oil pipeline optimisation, oil reservoir modelling and, of course, studies of the subatomic structure of matter itself.

With science in decline in many universities, to the point where some physics departments have lost autonomous existence, the researchers are excited that their discipline is producing such powerful and immediate applications.

"It is remarkable that forefront research in fundamental physics continues to lead to important practical consequences; usually totally unseen," says Professor Tony Thomas, Director of the Special Research Centre for the Subatomic Structure of Matter. "High energy physics gave us the World Wide Web with all of its commercial spin-offs, now abstract calculations in lattice gauge theory are expanding the limits of high performance computers. These are not only affordable, but will vastly improve our ability to model weather, climate change and water supplies, to identify just a few applications," he says.

Professor Williams agrees. "We are presently at the cutting edge in this field," he says, "And our researchers in physics, computing science, engineering, and energy and resource management are well poised to capitalize on our initial investment of expertise in this area."

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