Exchange 2007 Disk Performance/Partition Alignment - A Little Quickie
A perennial recommendation to squeeze the utmost in performance from your Exchange 2007 (and Exchange 2000 and Exchange 2003...) disk spindles has been to align the partition boundaries of the disks to a 8 KB boundary - since Exchange will always read in 8 KB at a time (or a multiple of that up to a megabyte). It means that, most often, a physical read and a logical read will map one-for-one - and your I/O will be the most efficient.
Well, in Windows Server 2008 you don't have to do this. Windows Server 2008 automatically aligns the beginning of a partition to a 1,024 KB boundary. Since Exchange 2007 service pack 1 is the first version of Exchange to run on Windows Server 2008, it means that you get this "for free" by installing your Exchange Server using Windows Server 2008. It's just lagniappe!
Note: this is also considered a best practice for SQL Server 200x.
References: Why should you use Diskpar (Diskpart in W2003 SP1), Partition Design, How to Align Exchange I/O with Storage Track Boundaries, and KB 929491.
P.S.: Vista also does this alignment.