Tianhe-I, Tianhe-1, or TH-1 (Chinese: 天河一号, [tʰjɛ́nxɤ̌ íxâʊ]; Sky River Number One)[3] is a supercomputer capable of an Rmax (maximum range) of 2.5 peta FLOPS.

[4][5] In October 2010, an upgraded version of the machine (Tianhe-1A) overtook ORNL's Jaguar to become the world's fastest supercomputer, with a peak computing rate of 2.57 petaFLOPS.

[12] Tianhe-1 was developed by the Chinese National University of Defense Technology (NUDT) in Changsha, Hunan.

2,048 FeiTeng 1000 SPARC-based processors are also installed in the system, but their computing power was not counted into the machine's official LINPACK statistics as of October 2010.

[21] The system has 3584 total blades containing 7168 GPUs, and 14,336 CPUs, managed by the SLURM job scheduler.

[18] Another significant reason for the increased performance of the upgraded Tianhe-1A system is the Chinese-designed NUDT custom designed proprietary high-speed interconnect called Arch that runs at 160 Gbit/s, twice the bandwidth of InfiniBand.

Tianhe-IA was ranked as the world's fastest supercomputer in the TOP500 list[27][28] until July 2011 when the K computer overtook it.

In June 2011, scientists at the Institute of Process Engineering (IPE) at the Chinese Academy of Sciences (CAS) announced a record-breaking scientific simulation on the Tianhe-1A supercomputer that furthers their research in solar energy.