US Patent 7426656 Method and system executing user programs on non-deterministic processors

A method and system of loosely lock-stepped non-deterministic processors. Some exemplary embodiments may be a processor-based method comprising executing fault tolerant copies of a user program, one copy of the user program executed in a first processor performing non-deterministic execution, and a duplicate copy of the user program executing in a second processor performing non-deterministic execution, with the executing in the first processor and second processor not in cycle-by-cycle lock-stepped.