This paper revisits replication coupled with checkpointing for failstop errors. Replication enables the application to survive many fail-stop errors, thereby allowing for longer checkpointing periods. Previously published works use replication with the no-restart strategy, which works as follows: (i) compute the application Mean Time To Interruption (MTTI) M as a function of the number of processor pairs and the individual processor Mean Time Between Failures (MTBF); (ii) use checkpointing period T no MTTI = √ 2MC à la Young/Daly, where C is the checkpoint duration; and (iii) never restart failed processors until the application crashes. We introduce the restart strategy where failed processors are restarted after each checkpoint. We compute the optimal checkpointing period T rs opt for this strategy, which is much larger than T no MTTI , thereby decreasing I/O pressure. We show through simulations that using T rs opt and the restart strategy, instead of T no MTTI and the usual no-restart strategy, significantly decreases the overhead induced by replication, in terms of both total execution time and energy consumption.