Anatomy of a Supercomputer
Gordon Haff, an analyst with Illuminata, said IBM is following a trend within HPC (high-performance computing) toward hybrid, heterogeneous offerings that use a combination of chips to accelerate different tasks. "We have been in this path toward very general-purpose computing for a while now, and you are starting to see a lot of people talk about ways to basically combine different types of processing elements," Haff said. "The really hard part here is the software, because we don't have very good programming models to handle heterogeneous processing, but the supercomputer, high-performance computing folks, particularly at the extreme high end, are much more tolerant of programming difficulty given the type of performance they need."Analysts and vendors say technology that is introduced in HPC often trickles down into the enterprise. For example, Grice said financial firms are always anxious to get hold of supercomputing technology, which can be used to speed up transactions and data-intensive calculations. In addition to incorporating Cell into the system, Grice and his colleagues also turned to standard IBM parts and other commodity components. Roadrunner will use AMD processors and IBM blades, and the system will run Red Hat's Fedora Linux operating system exclusively. At the heart of Roadrunner is what IBM calls a triblade, a node made up of two BladeCenter QS22 blades that contain four Cell processors and an LS21 blade with two Opteron chips. IBM engineers then used a PCI Express cable to connect each of the Opteron cores to a corresponding Cell processor. With Roadrunner and new QS22 blades that IBM brought out May 13, the company is using a variation on the Cell processor called PowerXCell 8i, which allows for "native" double-precision computing, doubling the blade's capacity to process data. This is essential to scientific applications. When Roadrunner is reassembled in Los Alamos later in 2008, it will comprise a series of what IBM calls "connected units," with each containing a Voltaire InfiniBand switch. Each unit is made up of 16 racks and contains 180 of the specially made triblades. Altogether, the installation at Los Alamos will have 18 of these connected units, which should offer a sustained petaflop of performance. With Roadrunner, Grice said IBM is following a path to increasing the power of supercomputers that the industry has followed during the last 30 years. Grice estimated that the performance of the top machine on the Top 500 list grows by 1,000 every 10 years. "There is no limit to the demand of what scientists and the financial people will want to do," Grice said.
According to IDC, the market for HPC servers grew 15.5 percent in 2007, to $11.6 billion. The research company said it expects the market to reach $15 billion by 2011.