Hardware Reference
In-Depth Information
Although these OSs automatically create 4K aligned partitions, you can manually create aligned
partitions for OSs that don't automatically create them, such as Windows XP. There's an easy way to
do this; use an OS that does create aligned partitions to first partition the drive, and then install the
older OS into the already existing aligned partition. For example, when installing XP onto a new 4K
sector HDD or solid-state drive (SSD), first attach the drive to a system running Vista or later and
create and format a single partition, which will be automatically aligned. Then simply install XP into
the existing (aligned) partition.
Note
For more information about using large sector drives with Windows (including updates needed
for some versions of Windows), see the Microsoft Knowledge Base article number 2510009,
“Information about Microsoft support policy for large sector drives in Windows,” at
You can use at least two methods to check the alignment of a partition under Windows. One is to open
a command prompt and enter the following command:
wmic partition get Name, StartingOffset
The command result shows the starting offset of all the partitions on all the drives connected to the
system. For example, here is the output after running the command on a system with two drives
installed, each with a single primary partition:
Name StartingOffset
Disk #0, Partition #0 32256
Disk #1, Partition #0 1048576
Another method is to run the msinfo32.exe program at a command prompt or via the Start menu under
All Programs, Accessories, System Tools, System Information. Once the program is running, in the
left pane select Components, Storage, Disks. Then, in the right pane find the Partition and Partition
Starting Offset figures for each of the drives/partitions in the system.
In this example, the first drive has a starting offset of 32,256 bytes. To see if this would be aligned on
a 4K sector drive (or SSD), divide that number by 4,096. The result is 7.875, which is not an even
number, indicating that this partition is
not
aligned. This is in fact the standard offset created by a
non-4K aware OS such as Windows XP, and it is equal to 63×512 bytes, indicating that the partition
