IBMs Roadrunner Speeds Toward a Petaflop

A Piece of the Puzzle
When it’s complete, Roadrunner will take up 6,000 square feet and weigh more than 500,000 pounds. Here’s one of the 18 different “connected units” that will make up Roadrunner.

At the heart of Roadrunner is a special server node that IBM calls a triblade. This specially designed server is made up of two QS22 blades and an LS21 blade.

What makes Roadrunner unique is that IBM will use its Cell processor, originally designed for game consoles, as a way to accelerate the more difficult scientific calculations that the supercomputer will perform during its time in Los Alamos. This is the inside of the QS22 blade, which holds the Cell processors. Roadrunner uses two QS22 blades with a total of four cell processors.

The LS21 blades use dual-core processors from AMD. This part of the machine handles the more basic computing, while the Cell-based servers are used to speed up the applications when needed.

IBM turned to mostly commodity parts to create Roadrunner. Here, the blades are arranged inside a typical BladeCenter H chassis, which helps support 180 of the triblades in each rack.

In keeping with its focus on commodity parts, the engineers at Los Alamos requested that IBM use Voltaire InfiniBand switches in the racks.

In putting together Roadrunner, IBM engineers needed to run miles and miles of fiber-optic cabling to connect the various pieces into one supercomputer. All together, IBM estimated that it used 57 miles of fiber-optic cabling in Roadrunner.

Each section of Roadrunner contains a console used to interface with the supercomputer. In this case, each resembles an older ThinkPad model; an icon for Red Hat Linux, the operating system, is visible in the corner.

IBM is currently testing Roadrunner at its facility in upstate New York. The company is preparing to disassemble it in a few weeks and ship the system out to New Mexico. There, sometime in August, engineers will reassemble the supercomputer.