Special-purpose supercomputers

Special-purpose supercomputers are high-performance computing devices with a hardware architecture dedicated to a single problem. This allows the use of specially programmed FPGA chips or even custom VLSI chips, allowing higher price/performance ratios by sacrificing generality. They are used for applications such as astrophysics computation and brute-force codebreaking. Historically a new special-purpose supercomputer has occasionally been faster than the world's fastest general-purpose supercomputer, by some measure. For example, GRAPE-6 was faster than the Earth Simulator in 2002 for a particular special set of problems.

Examples of special-purpose supercomputers:

• Deep Blue, for playing chess

• Reconfigurable computing machines or parts of machines

• GRAPE, for astrophysics and molecular dynamics

• Deep Crack, for breaking the DES cipher

The fastest supercomputers today Measuring supercomputer speed

The speed of a supercomputer is generally measured in "FLOPS" (FLoating Point Operations Per Second), commonly used with an SI prefix such as tera-, combined into the shorthand "TFLOPS" (10¹² FLOPS, pronounced teraflops), or peta-,combined into the shorthand "PFLOPS" (10¹⁵ FLOPS, pronounced petaflops.) This measurement is based on a particular benchmark which does LU decomposition of a large matrix. This mimics a class of real-world problems, but is significantly easier to compute than a majority of actual real-world problems.

The Top500 list

Since 1993, the fastest supercomputers have been ranked on the Top500 list according to their LINPACK benchmark results. The list does not claim to be unbiased or definitive, but it is the best current definition of the "fastest" supercomputer available at any given time.

Current fastest supercomputer system

As of August 2007, the IBM Blue Gene/L at LLNL is the fastest operational supercomputer, with a sustained processing rate of 280 TFLOPS.[2] [3] [4] On June 26, 2007, IBM unveiled Blue Gene/P, the second generation of the Blue Gene supercomputer. These computers can sustain one PFLOPS. IBM has announced that several customers will install these systems later in 2007. One of these is likely to become the fastest deployed supercomputer at that time. [5]

The MDGRAPE-3 supercomputer, which was completed in June 2006, reportedly reached one PFLOPS calculation speed, though it may not qualify as a general-purpose supercomputer as its specialized hardware is optimized for molecular dynamics simulations. See: [6] [7] [8]

Quasi-supercomputing

Some types of large-scale distributed computing for embarrassingly parallel problems take the clustered supercomputing concept to an extreme. One such example is the BOINC platform which is a host for a number of distributed computing projects recorded on March 27th 2007 processing power of over 530.7 TFLOPS through 1,797,000 plus computers on the network [9]. On March 27th 2007 BOINC's largest project SETI@home has a reported processing power of 276.3 TFLOPS through 1,390,000 plus computers [10].

On May 16, 2005, the distributed computing project Folding@home reported a processing power of 195 TFLOPS on their CPU statistics page.[11]. Still higher powers have occasionally been recorded: on February 2, 2005, 207 TFLOPS were noted as coming from Windows, Mac, and Linux clients [12].

Folding@home has started seeing even higher rates since PS3 game consoles have begun to contribute. After some initial reports of nearly a PFLOPS Folding@home has re-evaluated its measuring parameters for the PS3. Current (early September 2007) rates are steady at around 900 TFLOPs.

GIMPS's distributed Mersenne Prime search achieves currently 20 TFLOPS.

Google's search engine system may be faster with estimated total processing power of between 126 and 316 TFLOPS. The New York Times estimates that the Googleplex and its server farms contain 450,000 servers.^[1]