Recovering from loss of lock step

An apparatus, operating on an advanced multi-core processor architecture, and a corresponding method, are used to enhance recovery from loss of lock step in a multi-processor computer system (100). The apparatus for recovery from loss of lock step includes multiple processor units (111, 113; 121, 123; 125, 127) operating in the computer system, each of the processor units having at least two processor units operating in lock step, and at least one idle processor unit operating in lock step; and a controller (130) coupled to the two processor units operating in lock step and the idle processor unit. The controller includes mechanisms for copying an architected state of each of the two lock step processor units to the idle processor unit.