IBM's Blue Gene platform still heads the Top 500 list of supercomputers.
Big Blue has retained the number-one spot on the six-monthly list, thanks to the BlueGene/L System at the US Department of Energy's Lawrence Livermore National Laboratory.
The system recently recorded an industry Linpack benchmark performance of 280.6 teraflops (trillions of calculations per second).
No other system has so far exceeded the 100-teraflop mark. IBM-built machines accounted for around half of the systems in the Top 500, with HP making up around a third of the list.
Intel microprocessors drive 301 of the systems compared with 333 in the previous list. AMD Opteron processors accounted for 81 systems, compared with just 25 a year ago.
Almost 300 of the top supercomputers are in the US; while Europe has just 83 – down from 100 six months ago.