Slowing down Vista with SP1

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.

XP outperforms both versions of Vista by a wide margin. I found that it's three times as fast as both versions of Vista copying a folder of files to a local disk, and more than twice as fast as both versions of Vista when copying a folder of files to a network folder. XP is slightly slower than pre-SP1 Vista when it comes to copying a single 2.49 GB file to a local folder, and slightly faster than SP1 Vista. And XP is slower than both versions of Vista when it comes to copying a single 2.49 GB file to a network folder.

First, some background about the tests. I created four test benchmarks on the same machine, a dual boot XP-Vista laptop with a 1.83 Ghz Duo Core processor and 1 GB of RAM. First, in XP, I copied one 256 MB folder filled with 63 files and subfolders to a local disk and then to a network disk on another machine. Then, still in XP, I copied one 2.49 GB file to a local disk, and to a network disk on another machine. Then I rebooted into pre-SP1 Vista and performed the sets of tests. After that, I upgraded Vista to SP1 on the machine, and performed the same tests

In all instances on all versions of Windows, I did the test several times before recording results, in case any caching was going on, or in case Vista's SuperFetch technology came into play. And I performed each test at least three times and averaged the results to make sure everything was accurate.

I found that copying a 2.49 GB file under SP1 from one folder to another on a local machine was 20% slower than on pre-SP1 Vista. On SP1 Vista, it took 193 seconds; pre-SP1 Vista, it took 161 seconds. On XP, it took 178 seconds. The following graph shows details. (Note that Excel won't let me set the scale starting at 0 for some odd, unexplained reason, so it starts at 140 seconds.)

 

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:

Hands-on Vista SP1: Better but slower?