The long-awaited Service Pack 1 update for Windows Vista brings with it a number of significant bug fixes and other improvements. Microsoft says that with it you will also see a number of noticeable performance improvements as well. In our initial round of testing, we saw a mixed bag of results: we saw a few notable performance improvements under some conditions as well as significant performance degradations in others. For the most part, however, we saw little difference in performance between Vista and the Vista SP1 update.