Wei-Wu Hu received his B.S. degree from University of Science and Technology of China in 1991 and his Ph.D. degree from the Institute of Computing Technology, the Chinese Academy of Sciences in 1996, both in computer science. He is currently a professor in the Institute of Computing Technology. His research interests include high performance computer architecture, parallel processing and VLSI design.E-mail: {hww, hourui, xiao_jh, lbzhang}@ict.ac.cn Rui Hou is currently a Ph.D. candidate in Institute of Computing Technology, the Chinese Academy of Sciences. His research interest includes high performance computer architecture. Jun-Hua Xiao is currently a Ph.D. candidate in Institute of Computing Technology, the Chinese Academy of Sciences. His research interest includes high performance computer architecture. Long-Bin:i Zhang received the Ph.D. degree from the University of Science and Technology of China in 2002. And he completed the postdoctoral work in Institute of Computing Technology, Chinese Academy of Sciences, in 2004. He is now an associate researcher in Institute of Computing Technology, Chinese Academy of Sciences. His research interests includemicroprocessor design, system architecture, and cluster computing.