A FLOP (floating point operation) is an arithmetic operation, such as addition or multiplication, on numbers in scientific notation. It is generally the most complex of basic computer operations.

In order to achieve this groundbreaking speed in such a short time, IBM researchers are experimenting with ways to simplify traditional computer architectures, allowing chips to achieve performance improvements at a much faster pace than the current roadmap for today's chips.

IBM researchers are calling their experimental new design "SMASH," which stands for Simple, Many, And Self-Healing. "Simple" refers to the elemental architecture; "Many" describes Blue Gene's one million processors working in parallel; and "Self-Healing" means greater fault-tolerance and system stability. This experimental architecture should allow for more processors in less space using less power, resulting in more operations overall. Researchers expect this massively parallel system to be capable of eight million simultaneous threads of computation (compared to the maximum of 5000 threads today).

The details on SMASH

This approach will require researchers to explore significant departures from traditional computer design, including:

Embedded memory: The dynamic random access memory (DRAM) will be on the chips, making the memory much more accessible to the processors and radically improving access time and bandwidth. Tightly integrating the logic and memory like this also significantly reduces power requirements.

Minimalist design: By simplifying the overall architecture and using so many processors in parallel, Blue Gene will achieve incredibly fast system performance. Also, because the entire system will be built by replicating one chip 32,000 times, the overall project complexity is greatly reduced.

Multi-threading: Each processor is like a cook preparing eight recipes at once -- the cook starts one dish mixing, then moves to the next recipe, and so on. By the time the cook gets the eighth recipe started, the first is ready for its next step. In computer design, this is called multi-threading, and a primary goal for computer scientists is to keep the "cook" as busy as possible. Blue Gene will have one million of these "cooks," working on eight million concurrent "recipes" or threads.

High communication bandwidth: Blue Gene will have extremely high communication bandwidth among its chips, allowing them to exchange massive amounts of data faster than ever before. With six channels on each chip, each channel sending data at two gigabytes per second, the total communication is 300 terabytes per second. In fact, the aggregate communication bandwidth of Blue Gene is roughly equal to every one of the six billion people in the world operating four ISDN modems simultaneously. If you could harness Blue Gene's bandwidth to download the entire contents of the Internet -- all 100 terabytes -- it would take less than a second.

Self-Healing: The self-healing aspect of Blue Gene's architecture is one of the biggest challenges the research team faces. The hardware -- with its tremendous redundancy in processor and communication paths -- makes this concept feasible since it provides many routes to access a processor, and many processors over which to distribute calculations. Self-management is a huge challenge for a machine of this scale. IBM's software researchers are exploring advanced technologies for distributed control and recovery to insure that Blue Gene runs continuously.

Small footprint delivers big power

The final machine will have 64 interconnected racks, each rack containing eight boards, each board containing 64 chips, and each 20x20 mm chip comprised of 32 processors. Each processor will operate at one gigaflop, which is one billion operations per second.

Just one of Blue Gene's processor boards (a two-foot by two-foot component) will be capable of two teraflops -- the same raw computational power as the ASCI Blue Pacific supercomputer that IBM installed earlier this year at Lawrence Livermore National Laboratory.

Upon completion, Blue Gene will occupy less than 2,000 square feet, taking up much less space than the 8,000 square feet needed to house the world's largest computer today. At a speed of one petaflop, Blue Gene will be:

• 500 times more powerful than the fastest computer in the world today;
• 1,000 times more powerful than Deep Blue;
• 40 times faster than the sum power of the 40 fastest supercomputers in the world today;
• two million times more powerful than today's top desktop PC.