Next, our own in-house Photoshop Elements and Virtual Dub tests:
Again, there is some improvement in both tests, though it's relatively minor in nature, with a 27 second improvement in the Photoshop test and 20 seconds in Virtual Dub rendering test. Obviously, these are very small percentage changes, which only provide a vague idea of whether performance has really improved.
Indeed, this is overriding conclusion of this admittedly quick and dirty test of SP1 Release Candidate 1. From the PCMark Vantage results it's possible to conclude that there's been some improvement in how Vista deals with multiple simultaneous threads, though it's also possible that that this can be attributed to updates to IE7, which is used for the web page rendering test that form a large part of the Communications tests.
However, these are synthetic tests, which can only show you so much. Thus, following the Christmas break I'll be reporting back with a more general real-world impression of how SP1 RC1 influences performance, looking specifically at stability, responsiveness and issues such as file copying and network performance, which have been issues in the past. Until then, why not let us know about your experiences in the forums?