Naja bei Google ist dieser Thread mit dem Schlagwort Lock Stepping das 3. Ergebnis
"Performing two operations at the same time such as updating two databases or executing two instructions. The term is often used to refer to instruction lock stepping, in which two CPUs execute the same instructions and compare the results. If the results of the two operations are not identical, one of the CPUs is failing, and the system has to perform a series of tests to determine which one is bad."