Linux Case Studies

Article: Linux Helps Bring Titanic to Life

Alpha + Linux = Supercomputer For Less

By Andy Patrizio, TechWeb

Researchers at the Los Alamos National Laboratory, Los Alamos, New Mexico, are usually researching obscure sciences like theoretical physics simulations, but they have also invented a supercomputer made of off-the-shelf parts running a powerful -- and free -- operating system.

The computer, called Avalon, consists of 68 computers with Alpha central processing units (CPUs), networked together with Fast EtherNet and running the Linux OS. Linux is a free Unix derivative that first began on Intel, but has been ported to a number of other platforms, including Alpha.

While supercomputers usually cost millions of dollars, the total for Avalon came to only $150,000, all of it hardware. The lab used Red Hat Linux 5.0, published by Red Hat Software; if it had used Digital's Unix variant, the OS would have cost more than the hardware, said Michael Warren, lead designer of the computer.

The pieces for the computer arrived on a Friday and by the following Monday, the development team had the system running at 10 gigaflops per second, well in the range of supercomputing. They later got it to run at 19.2 Gflops per second, ranking it as the 315th fastest supercomputer in the world, according to a list of the 500 fastest supercomputers, published at the Supercomputer 98 conference in Mannheim, Germany last month.

Avalon's performance is comparable to a 64-processor Origin 2000 from Silicon Graphics, which has a list price of $1.8 million, said Warren.

Linux also did the job extremely well. "It's absolutely more robust than Solaris," said Warren. "We've had 80 nodes running Linux for two months now and have had only one problem due to disk errors. It offers good performance, we don't have to pay $500 per CPU, and it's got open source code so we can modify things and fix them when they break."

That said, no changes were made to the kernel or the networking code out of the box to get maximum network and OS performance, he said. "The main performance bottleneck in machines of this type are the networking protocols," said Warren. "The performance in Linux has been remarkable. We're getting full wire speed through Fast EtherNet. You couldn't get more speed by tweaking."

Chris Willard, research director for high performance technology at Dataquest, called Warren and his team "very, very smart people," but said the Avalon system is not practical for most corporations.

"You might see it in an R&D lab, but it won't be running an Oracle database," he said. "Wiring something yourself and putting a million dollars of business per day on it is not a good business decision."

Avalon also makes Linux look good. But it still has its shortcomings, Willard pointed out. "As you move further and further into mainstream products, people look for specific features," he said. "How well does it handle drive tapes? How well does it do RAID [Redundant Array of Independent Disks]? Things of that type become an issue."


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