High power-performance ratio is the most important factor in high-performance computing, whose performance is limited by its power budget. A SuperH TM (SH) embedded processor core, SH-X3, implemented in a 90-nm CMOS process running at 600 MHz achieved 1080 Dhrystone MIPS, 4.2 GFLOPS, and 55M polygons/s. Its power performance ratio reaches to as high as 3000 MIPS/W. It is, therefore, a candidate processor for high-performance computing. This paper focuses on the SH processors' low power features, floating-point architecture and performance, and applicability to the highperformance computing.