A colleague, Piers Williams, mentioned the topic of disk partition alignment to me last week, and Microsoft have recently released a whitepaper on this “essential yet often overlooked” subject.
In Windows Vista as well as Windows Server 2008, partition alignment is usually performed by default. The default for disks larger than 4 GB is 1 MB; the setting is configurable in the registry.
On the other hand, partitions created on versions of Windows up to and including Windows Server 2003 by default are not aligned. Partition alignment must be explicitly performed.
There must be hundreds of thousands of systems out there incorrectly aligned, and consequently under-performing.