Chris:

I have battled with the same question for a while here. You did not give the exact offset that you are getting, nor the SAN Vendor.

If NetApp, I will suggest you read up on:

a) How to diagnose misaligned I/O on Windows hosts

https://kb.netapp.com/support/index?page=content&id=1010803

Windows_2008:

In Windows, click Start > Run > then enter msinfo32.exe to run System Information.

Select Components > Storage > Disks. Scroll to the bottom and you will see the Partition Starting Offset information. This number should be 65535 bytes for LUNs smaller than 4GB or 1048576 bytes for LUNs that are 4GB or larger.

Also, consider issuing :

fsutil fsinfo ntfsinfo <logical-drive>

and check on the "Bytes per Cluster".

and wmic partition get BlockSize, StartingOffset, Name