Performance of a new system may be optimized to run a legacy application written for a legacy system. Performance information for the legacy application is recorded or derived while running the legacy application on the new system. Performance characteristics for the legacy application running on the new system are determined by analyzing the performance information. The performance characteristics include one or more key performance metrics and other performance information. The key performance metrics must be met when the legacy application is run on the new system. The other performance information is useful for adjusting one or more operating parameters of the new system when running the legacy application on the new system. The one or more operating parameters are adjusted so that the one or more key performance metrics are met.