Modern multicore platforms allow system administrators to reduce the costs of the IT infrastructure by consolidating heterogeneous workloads on the same physical machine. To this end, it is important to develop efficient profiling techniques and accurate performance predictions to avoid violating service-level objectives. In this work we present Tresa, a novel tool to automatically characterize workloads and accurately estimate the execution time of different consolidations. These results can be used to optimize consolidations depending on service-level objectives. Copyright 2012 ACM.