A multiprocessor system includes a number of sub-processor systems, each substantially identically constructed, and each comprising a central processing unit (CPU), and at least one I/O device, interconnected by routing apparatus that also interconnects the sub-processor systems. A CPU of any one of...http://www.google.com/patents/US6496940?utm_source=gb-gplus-sharePatent US6496940 - Multiple processor system with standby sparing
