The SX-9 is a supercomputer built by NEC Corporation. The SX-9 Series implements an SMP system in a compact node module and uses an enhanced version of the single chip vector processor that was introduced with the SX-6. The NEC SX-9 processors run at 3.2 GHz, with eight-way replicated vector pipes, each having two multiply units and two addition units; this results in a peak vector performance of 102.4 gigaFLOPS. For non-vectorized code, there is a scalar processor that runs at half the speed of the vector unit, i.e. 1.6 GHz. Up to 16 CPUs and 1 terabyte of memory may be used in a single node. Each node is packaged in an air-cooled cabinet, similar in size to a standard 42U computer rack. The SX-9 series ranges from the single-node SX-9/B system with 4 CPUs to the maximum expansion stage with 512 nodes, 8,192 CPUs, and 970 TFLOPS peak performance. There is up to 4 TB/s shared memory bandwidth per node and 2×128 GB/s node interconnect bandwidth. The operating system is NEC's SUPER-UX, a Unix-like OS.
The SX-9 has the world's fastest vector CPU core. A fully equipped system with 512 nodes would be the world's fastest vector supercomputer at the time of release in the first quarter of 2008.
The German national meteorological service (DWD) operates two independent SX-9 clusters, with 976 processors, 31,232 GB of RAM and 98 TFLOPS performance in total.