Since 1993, the TOP500 project has been publishing a semi-annual list of the 500 most powerful computer systems in the world, as a barometer of trends and accomplishments in high-performance computing. The systems are ranked based on their speed in floating-point operations per second (FLOP/s), measured on the LINPACK benchmark, which involves the solution of a dense system of linear equations.
The most recent list has just been released, in conjunction with the International Supercomputing Conference now underway in Hamburg, and there is a new speed champion in Japan.
The system, called the K Computer, is at the RIKEN Advanced Institute for Computational Science (AICS) in Kobe. …
The K Computer, built by Fujitsu, currently combines 68544 SPARC64 VIIIfx CPUs, each with eight cores, for a total of 548,352 cores—almost twice as many as any other system in the TOP500.
No single number can capture every aspect of a system’s performance, but the K Computer achieves a LINPACK speed of 8.16 petaFLOP/s (8.16 × 1015 floating point operations per second). For the first time, all of the top 10 systems on the list achieve petaFLOP/s performance. Five of the top ten systems are in the United States, with two in Japan, two in China, and one in France.
As you might expect, the K Computer requires a fair amount of electric power — 9.89 megawatts, in fact — but in terms of energy consumption, it is actually quite efficient, delivering 825 megaFLOPs per watt, making it the fourth-most energy efficient system on the list. The average energy efficiency of the Top 500 systems is 248 megaFLOP/s per watt, improved from 219 megaFLOP/s per watt just six months ago.
As has been true for some time, the distribution of operating systems used is rather different from that in the desktop computing market:
| OS Family | Number | % of Capacity |
|---|---|---|
| Linux | 455 | 91.0 |
| Unix | 23 | 4.6 |
| BSD-based | 1 | 0.2 |
| Windows | 6 | 1.2 |
| Mixed | 15 | 3.0 |
Also, as I noted with respect to previous lists, the use of commodity processors (CPUs) is very much the norm.
Random Walks 
[…] and will have 1.6 petabytes of memory. (For comparison, the fastest system on this year’s Top 500 List, the K Computer at the RIKEN Advanced Institute for Computational Science, in Kobe, Japan, cranks […]