The supercomputer, for the Los Alamos National Laboratory, will be the world's fastest machine and is designed to sustain a performance level of a "petaflop," or 1 quadrillion calculations per second, said U.S. Sen. Pete Domenici earlier this year. Bidding for the system opened in May, when a congressional subcommittee allocated $35 million for the first phase of the project, said Domenici, a Republican from New Mexico, where the nuclear weapons lab is located.
Now sources familiar with the machine have said that IBM has won the contract and that the National Nuclear Security Administration is expected to announce the deal in coming days. The system is expected to be built in phases, beginning in September and finishing by 2007 if the government chooses build the full petaflop system.
There's plenty of competition in the high-end supercomputing race, though. Japan's Institute of Physical and Chemical Research, called RIKEN, announced in June that it had completed its Protein Explorer supercomputer. The Protein Explorer reached the petaflop level, RIKEN said, though not using the conventional Linpack supercomputing speed test.
Representatives of IBM and Los Alamos declined to comment for this story. The NNSA, which oversees U.S. nuclear weapons work at Los Alamos and other sites, didn't immediately respond to a request for comment.
The Roadrunner system, along with the Protein Explorer and the seventh-fastest supercomputer, Tokyo Institute of Technology's Tsubame system built by Sun Microsystems, illustrate a new trend in supercomputing: combining general-purpose processors with special-purpose accelerator chips.
"Roadrunner is emphasizing acceleration technologies. Coprocessor acceleration is intrinsic to that particular design," said John Gustafson, chief technology officer of start-up, which sells the accelerator add-ons used in the Tsubame system. (Gustafson was referring to the Roadrunner project in general, not to IBM's winning bid, of which he disclaimed knowledge.)
IBM's BladeCenter systems are amenable to the hybrid approach. A single chassis can accommodate both general-purpose Opteron blade servers and Cell-based accelerator systems. The BladeCenter chassis includes a high-speed communications links among the servers, and one source said the blades will be used in Roadrunner.
is used in supercomputing "cluster" systems that spread computing work across numerous small machines joined with a high-speed network. In the case of Roadrunner, , provides the special-purpose accelerator.
Cell originally was designed to improve video game performance in the PlayStation 3 console. The single chip's main processor core is augmented by eight special-purpose processing cores that can help with calculations such as simulating the physics of virtual worlds. Those engines also are amenable to scientific computing tasks, IBM has said.
Using accelerators "expands dramatically" the amount of processing a computer can accomplish for a given amount of electrical power, Gustafson said.
"If we keep pushing traditional microprocessors and using them as high-performance computing engines, they waste a lot of energy. When you get to the petascale regions, you're talking tens of megawatts when using traditional x86 processors" such as Opteron or Intel's Xeon, he said.
"A watt is about a dollar a year if you have the things on all the time," so 10 megawatts per year equates to $10 million in operating expenses, Gustafson said.
A new partnership
The Los Alamos-IBM alliance is noteworthy for another reason as well. The Los Alamos lab has traditionally favored supercomputers from manufacturers other than IBM, including Silicon Graphics, Compaq and Linux Networx. Its sister lab and sometimes rival, Lawrence Livermore, has had the Big Blue affinity, housing the current top-ranked supercomputer, Blue Gene/L.
Lawrence Livermore also houses earlier Big Blue behemoths such as, White and . (ASCI stood for the Accelerated Strategic Computing Initiative, a federal effort to hasten supercomputing development to perform nuclear weapons simulation work, but has since been modified to the Advanced Simulation and Computing program.)
Blue Gene/L has a sustained performance of 280 teraflops, just more than one-fourth of the way to the petaflop goal.
The U.S. government has become an avid supercomputer customer, using the machines for simulations to ensure nuclear weapons will continue to work even as they age beyond their original design lifespans. Such physics simulations have grown increasingly sophisticated, moving from two to three dimensions, but more is better. Los Alamos expects Roadrunner will increase the detail of simulations by a factor of 10, one source said.
For twice-yearly ranking of supercomputers called the Top500 list, computers are ranked on the basis of a benchmark called Linpack that measures how many floating-point operations per second--"flops"--it can perform. Linpack is a convenient but incomplete representation of a machine's total ability, but it's nevertheless widely watched.
IBM has dominated the Top500 list with its Blue Gene/L supercomputing designs. But U.S. models haven't always led, and there's been some international rivalry: A Japanese system, NEC's Earth Simulator, topped the list for years.
IBM and petaflop computing are no strangers. Although customers can buy the current Blue Gene/L systems or rent their processing power from IBM,in 2000 to reach the petaflop supercomputing level.