Engineers and technicians at IBM are assembling the final pieces of what they hope will soon become the world's most powerful supercomputer - doubling the speed of the today's fastest machine.

The latest version of IBM's Roadrunner supercomputer is a hybrid machine that its builders expect will bust through the lofty petaflop barrier when it's tested this month.

Akin to the significance of breaking the four-minute mile in the supercomputing world, the petaflop barrier is a goal that many computer makers, including Cray, HP, Sun, and SGI, are shooting for. Don Grice, chief engineer on IBM's Roadrunner project, thinks it's a race that IBM will win.

"We will break the petascale barrier," he told Computerworld at IBM's Poughkeepsie, NY, facilities. "The only unknown for me will be what day it is. I don't think there's any technical reason we won't make it. The only hurdle left is persistence."

The new supercomputer will be used at the US Department of Energy's Los Alamos National Laboratory to work on national security problems, run annual tests of various nuclear weapons systems and predict long-term climate changes, according to John Morrison, leader of the high-performance computing division at Los Alamos. He noted that the system will also be used to study the universe and human genes.

"It will enable us to tackle problems we couldn't tackle before," he said. "Essentially, we'll be able to run a different level of problems. We'll be able to do calculations that we wouldn't even consider before." Morrison noted that the lab's contract calls for the new Roadrunner to reach the petaflop performance level.

Grice said the new machine would need a single week to run a calculation that the fastest supercomputer 10 years ago would have needed 20 years to complete.

If Roadrunner does break the petaflop barrier this month, it will mark the first time that IBM's BlueGene system hasn't held the highest position in the Top 500 supercomputer list since November of 2004, according to Jack Dongarra, a co-creator of the Top 500 list.

A petaflop is 1,000 trillion calculations per second. BlueGene runs at 478 teraflops, which is a trillion operations per second.

"It's exciting because it most likely will be the first computer to break the petaflop barrier," said Dongarra. "It's the next golden ring of computing. It's the next big marker. Today, all of the Top 500 supercomputers are at the teraflop rate."

The new IBM supercomputer is the second incarnation of Roadrunner. The original Roadrunner, a cluster machine that can hit 70 teraflops, is in use at the Los Alamos lab. The older Linux-based system runs AMD Opteron chips.

This new version of Roadrunner, also runs Linux and gets its hefty power boost by adding the Cell chips, originally designed jointly by IBM, Toshiba and Sony for the latter's PlayStation 3, to the Opteron base. The hybrid supercomputer will use the Cell chips for massive calculations.

"We had done enough studies to see that it's one of the best computational chips in the world," said Grice, who first thought of using the Cell chip in a supercomputer. "It was built to do high performance computations for video games. The aspects that make it really good for gaming, made it really good for supercomputing. It's not running anything to do with the [operating system]. It's focused solely on calculations."

The new Roadrunner uses 3.9 megawatts of power, which Grice noted is enough to power 39,000 100-watt light bulbs. It has 6,948 dual-core Opterons on IBM LS21 Blades, as well as 12,960 Cell processors on IBM QS22 blades. The machine, which has 80 terabytes of memory, has 296 IBM BladeCenter H racks. It takes up 6,000 square feet, uses 57 miles of fibre optic cable and weighs in at 500,000 pounds.

Once the IBM technicians finish testing it, they'll pack it up on 21 tractor trailer trucks and move it to Los Alamos in New Mexico, where they'll reassemble it and test it all over again.

IDC's Conway noted that the next several weeks should prove interesting. The Top 500 list of supercomputers will be updated on June 17 at the International Supercomputing Conference in Dresden, Germany. He says any company close to hitting a petaflop will be testing their supercomputers to try and make the list. "It has symbolic importance," said Conway. "It's like the four-minute mile. It gives people confidence that they can hit 10 petaflops and 1,000 petaflops."