Microsoft has been promoting Vista's SP1 as a big performance booster compared to pre-SP1 Vista, particularly when copying files. But my preliminary tests show that Vista SP1 can be as much as 20% slower than pre-SP1 when it comes to copying files. And XP's copying speed leaves both in the dust.
I found that copying a large file -- 2.49 GB -- to a local folder under SP1 Vista was 20% slower than performing the same operation in pre-SP1 Vista. Copying that same file to a network folder took essentially the same amount of time in pre-SP1 and SP1 Vista. And copying a 256 MB folder full of files to a local disk and to a network folder took essentially the same amount of time in each as well.
Copying the single 2.49 GB file to a network folder takes essentially the same amount of time in SP1 and pre-SP1: 233 seconds in SP1 versus 237 seconds in pre-SP1. Both versions of Vista beat XP, which came in at 296 seconds --- the only test in which XP was slower than both SP1 and pre-SP1. The following graph shows details.
When it comes to copying the 256 MB folder full of files, Vista SP1 and pre-SP1 performed just about identically, and dramatically slower than XP. Copying the folder to a local disk took 36 seconds in both versions of Vista, and only 12 seconds in XP. The following graph shows details.
Copying the folder full of files to a folder on another machine on the network took 101 seconds in Vista SP1, 98 seconds in pre-SP1, and only 39 seconds in XP, as you can see in the following graph.
The upshot of all this? On my test machine at least, copying in Vista SP1 is slightly slower than in pre-SP1, and much slower than in XP. There's of course one caveat here: These tests were performed on only one system, and as the saying goes, your mileage may vary. But on at least one machine, SP1 doesn't do as well as pre-SP1 when copying files.
See also, Preston Gralla's complete review: