How can I view the allocation unit size of a NTFS partition in Vista?
Open an administrator command prompt, and do this command:
fsutil fsinfo ntfsinfo [your drive]
The Bytes Per Cluster is the equivalent of the allocation unit.
Another way to find it quickly via the GUI on any windows system:
create a text file, type a word or two (or random text) in it, and save it.
Right-click on the file to show Properties.
"Size on disk" = allocation unit.
Use diskpart.exe.
Once you are in diskpart select volume <VolumeNumber> then type filesystems.
It should tell you the file system type and the allocation unit size. It will also tell you the supported sizes etc. Previously mentioned fsutil does work, but answer isn't as clear and I couldn't find a syntax to get the same information for a junction point.
I know this is an old thread, but there's a newer way then having to use fsutil or diskpart.
Run this powershell command.
Get-Volume | Format-List AllocationUnitSize, FileSystemLabel