By Noel Randewich

Nov 14 (Reuters) - The U.S. Department of Energy said on Friday it is spending $425 million to research extreme-scale computing and build two super-computers, which would be the world's fastest, for research into basic science as well as nuclear weapons.

The DOE is awarding $325 million to build "Summit" for Oak Ridge National Laboratory in Tennessee and "Sierra" at the Lawrence Livermore National Laboratory in California.

An additional $100 million will go to research into "extreme scale supercomputing" technology as part of a program called FastForward2, the DOE said in a news release.

The supercomputers, made with components from IBM, Nvidia and Mellanox, will run five to seven times faster than the United States' current fastest computers.

Summit and Sierra will operate at 150 petaflops and 100 petaflops, respectively, compared to the world's current top super-computer, the Tianhe-2 in China, which performs at 55 petaflops, Nvidia said in a separate news release.

IBM built the first supercomputer to reach 1 petaflop, a precise measure of how fast computers calculate, in 2008, also for the Department of Energy.

Researchers worldwide will be able to apply for time to use the Summit computer. The National Nuclear Security Administration will use Sierra "to ensure the safety, security and effectiveness of the nation's nuclear deterrent without testing," Nvidia said.

Santa Clara, California-based Nvidia is best-known for its high-end personal-computer graphics chips favored by gamers. In recent years it has developed more advanced versions of those chips suitable for parallel processing on supercomputers and in data centers.

It has also been working with IBM to develop future chip offerings for high-end enterprise customers.

(Reporting by Noel Randewich; Editing by Leslie Adler)