Copyright © 2007 IEEE. Reprinted from Proceedings of the 13 th International Symposium on High Performance Computer Architecture (HPCA). This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of the University of Maryland’s products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to pubs-permissions@ieee.org . By choosing to view this document, you agree to all provisions of the copyright laws protecting it.