There is an EMC whitepaper titled Using diskpar and diskpart to align partitions on Windows Basic and Dynamic Disks. This paper describes how legacy Windows issues cause a single disk I/O to span multiple tracks. This puts an unnecessary load on the SAN and reduces performance. The fix is to align the partition. Below is a sample session using the DISKPART utility. Comments are in red.
Microsoft DiskPart version 5.2.3790.3959
Copyright (C) 1999-2001 Microsoft Corporation.
On computer: MYTESTBOX
You must select the disk to act on
DISKPART> select disk 5
Disk 5 is now the selected disk.
Create a partition using the EMC-recommended alignment offset
DISKPART> create partition primary align=64
DiskPart succeeded in creating the specified partition.
Select the partition / volume that you just created
DISKPART> select volume=0
Volume 0 is the selected volume.
Assign a drive letter
DISKPART> assign letter=o
DiskPart successfully assigned the drive letter or mount point.
You can now use the disk management MMC to format the partition