Microsoft has talked and talked about how SP1 will give a big performance boost to Windows Vista, particularly when copying files. While everyone will be able to check performance for themselves next month when Microsoft finally releases SP1, the folks over at PCWorld have taken an RTM version of SP1 for a spin to see what kinds of improvements users can expect.

Shut down and boot appears to be slightly faster with SP1 installed. However, when it comes to file manipulation, results thus far have been a mixed bag. A large file copy involving 562 images for a total of 1.9GB from a 2GB Kingston SD Card to the PC was 9% quicker on SP1, while a couple of smaller file operations actually took about 3% longer on a test machine with SP1 installed. Check out PCWorld’s performance test results here, plus some less-promising ones at ComputerWorld.