With aggressive technology scaling, integrated circuits suffer from everincreasing wearout effects and their lifetime reliability has become a serious concern for the industry. For manycore processors that integrate a large number of processor cores on a single silicon die, introducing core-level redundancy is an effective way to alleviate this problem. There are, however, many strategies to make use of the redundant cores, which have different implications on the aging effects of embedded processors. How to characterize the lifetime reliability of manycore processors with different usages is therefore an important and relevant problem. In this paper, we propose a novel analytical method to tackle the above problem, which captures the impact of workloads and the associated temperature variations. We then use the proposed model to analyze the lifetime reliability for manycore processors with various redundancy configurations. Finally, the effectiveness of the proposed method is demonst...