Methods, systems, devices and computer program products are presented for requesting wireless device performance data and providing an optimal file size for the performance data. Present aspects provide for estimating the size of requested performance data, at the time of the request, and assessing other factors, such as requesting party preferences, to determine optimal performance data file size. In this regard, the performance data service provider is able to prepare and make accessible optimally sized performance data files, as the data becomes available as opposed to creating one comprehensive performance data file when all of the requested data is available. Additionally, some present aspects may provide for performance data requesting parties to implement Extensible Markup Language (XML) as the communication tool between the requesting device and the performance data-supplying network entity.