"Earth Simulator," a Japanese-made supercomputer retained the title of the world's fastest calculating machine last year, according a report published Monday in Heidelberg.

The 23rd edition of the TOP500 list of the world's fastest supercomputers, which released on the eve of the International Supercomputer Conference in Heidelberg, said that the supercomputer built by NEC and installed in 2002 at the Earth Simulator Center in Yokohama, Japan, has a performance of 35.86 teraflops.

One teraflop means one trillion of calculations per second, or 6,000 times than a modern personal computer.

The second fastest computer on the Top 500 list is "Thunder", an Intel Itanium2-based cluster system at Lawrence Livermore National Laboratory in California.

"ASCI Q" of Hewlett-Packard, which was number two in last year's list, has been edged to the third place in the new list.

For the first time, a Chinese-made computer has entered into the top 10. Number 10 on the list "Shuguang 4000A" was assembled by a Chinese firm with AMD's Opteron chip, the report said, adding that the performance of the Chinese system is 8.06 teraflops.

Shuguang has a Linpack benchmark performance of 8 teraflops per second, which means it can carry out four trillion of calculations in one second. Except for its CPU and a Linux operating system, all the parts of the supercomputer were made in China.

The TOP500 list is compiled by the University of Mannheim, Lawrence Berkeley National Laboratory and the University of Tennessee.