The SX-6 is a NEC SX supercomputer built by NEC Corporation that debuted in 2001; the SX-6 was sold under license by Cray Inc. in the U.S. Each SX-6 single-node system contains up to eight vector processors, which share up to 64 GB of computer memory. The SX-6 processor is a single chip implementation containing a vector processor unit and a scalar processor fabricated in a 0.15 μm CMOS process with copper interconnects, whereas the SX-5 was a multi-chip implementation. The Earth Simulator is based on the SX-6 architecture.