Virtual Duplex Systems with Forward Error Correction on Simultaneous Multithreaded Processors

Virtual Duplex Systems provide detection of and recovery from transient as well as most permanent hardware faults. In contrast to duplex systems, they do so by providing tem-poral instead of structural redundancy: one time-shared in-stead of two processors. Previous studies on virtual duplex systems have focussed on either improving fault coverage or reducing overhead. We build upon this work and in-vestigate the positive influence of an underlying processor hardware that supports multiple threads in hardware. Such processor architectures are just entering the market. Our findings are that those processors allow faster fault detec-tion and recovery than conventional processors of the same speed. Alternatively, a multithreaded processor can be run at a lower frequency to provide the same detection and re-covery rate as before.