After being dethroned by China as the world's fastest supercomputer maker, US has upped the ante and is creating two 20-petaflop supercomputers to reclaim the top position for the most powerful supercomputer.

A report by Computerworld  stated the new supercomputers will be the fastest with speeds of up to 20-petaflops. One of the new supercomputers will be built by Oak Ridge National Laboratory, where the former fastest supercomputer Jaguar is housed. The other one is being built at the Lawrence Livermore National Laboratory by IBM. The report also confirmed that the systems will be completed by 2012.

Recently China's supercomputer Tianhe-1A system, housed at the National Supercomputer Center in Tianjin, toppled Cray XT5 Jaguar to become the fastest supercomputer, recording speed of 2.57 petaflops.

The second position is held by Jaguar clocking 1.75 petaflops. According to the recent list by The Top 500 Supercomputers Sites, the third position is also held by a Chinese System called Nebulae which clocked 1.27 petaflops.

Currently five of the world's top 10 supercomputers are housed in the US while other five are located in China, Japan and Germany. However, five of the top 10 supercomputers are new in the list.

Also China has 42 systems in the Top 500 List of supercomputers ahead of Japan, France, Germany and UK and is positioned second to US in the number high performance computers in the list.

US is the largest user of High Performance Computers (HPC) with 275 of the top 500 systems, though the number has declined from 282 in June 2010.

The report by TOP500 Supercomputers also stated that Intel is still the preferred choice for supercomputers as 398 of the top 500 supercomputers are powered by Intel processors. Playing second fiddle to Intel is its rival AMD, powering 57 systems.

Also both the Chinese supercomputers in the top 10 list use NVIDIA GPUs as co-processors for acceleration. 17 of the top 500 supercomputers currently use GPUs.

Petaflop is a measure of a computer's processing speed and expressed as a thousand trillion operations per second.