Now two of the bloggers over at ZDnet have taken up the task to figure out whether Vista SP1 is at least as fast as XP SP2. Adrian Kingsley-Hughes' first round of testing over a period of days found Vista SP1 to be still much slower than XP SP2.

But Ed Bott decides to do a little testing of his own, using equipment that I agree is likely to be a better representation of what we're likely to see in the market today. What's interesting is that Ed's testing finds Vista to be "at least as fast or faster" on all but one of the tests.

What's the real answer, I dunno'. In my own experience I've found that Vista SP1's performance to be noticeably better than with RTM. In one particular example, I was copying about 25M of pictures off a digital camera and acutally had to complete the process twice. Why? Because Vista SP1 copied that data so fast that I didn't believe that it actually worked. Copying files from that camera used to be a long and painful process. After the update, the entire copy happened as fast as the mouse click.