The Top500 list of the world\u2019s fastest supercomputers was released Wednesday, with IBM\u2019s BlueGene continuing to reign and Advanced Micro Devices\u2019 (AMD\u2019s) Opteron processor powering more systems on the list than last year.Retaining the number-one spot on the biannual list for the fourth time, IBM\u2019s BlueGene\/L System at the U.S. Department of Energy\u2019s Lawrence Livermore National Laboratory recently reached a Linpack benchmark performance of 280.6 teraflops, or trillions of calculations per second. No other system has yet passed the 100 teraflop-per-second mark. IBM supercomputers accounted for about half of the overall list, with Hewlett-Packard taking nearly a third of the list, which was released at the International Supercomputing Conference in Dresden, Germany.The Top500 list, known for its rapid turnover, showed slower than average turnover rate this year. Some 158 systems were bumped this time around, compared to more than 200 systems displaced in the June 2005 list. But in the fast-paced world of high-performance supercomputing, no systems maker can afford to rest on its laurels for long, especially at the high end of the list. "The thresholds to get into the top 50 move fast; machines are there one day, gone the next," said Herb Schultz, manager for IBM Blue Gene."In the next six months, you should see discussions about what\u2019s next. It\u2019s no secret Blue Gene has been in the market for a little while, and we\u2019re looking at ways to make the chips faster, get more chips on a core and do a faster job of interconnecting nodes. So you could expect to see a product with the same architecture, but that\u2019s faster and maintains the same power and cooling envelope as the current Blue Gene does," Schultz said.Among other trends on the list, Intel microprocessors powered 301 of the systems, which was down from 333 last year, while AMD\u2019s Opteron processors gained some ground to account for 81 systems, compared to only 25 systems one year ago. Most of the supercomputers on the list, nearly 300, are housed in the United States. Europe now has 83 systems, which is down from 100 systems they had six months ago. Meanwhile, Asia has 93 systems, which is up from 66 six months ago.-Shelley Solheim, IDG News Service (New York Bureau)Check out our CIO News Alerts and Tech Informer pages for more updated news coverage.