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.

Easiest way, confirmed on 2012r2.

1. Go to "This PC"
2. Right click on the Disk
3. Click on Format

Under drop down "allocation unit size" will be the value of what the Allocation of the Unit size disk already is.

In a CMD (as adminstrator), first run diskpart. In the opened program, enter list disk. It'll list all connected disks.

Select the right disk based on its size. If it is flash memory, usually it'd be the last item in the list. In my case, I select the Disk 2 using this command: select disk 2.

After selecting your disk, list the partitions using list partion command. You'll get a list like the one in the image below.

Now, it is time to select the right partition, based on its size. In my case, I select Partition 1 using this command: select partition 1.

Finally, you can run the filesystem command to get the Allocation Unit Size.

Note: This procedure works on both NTFS and FAT32.