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I cloned a non Advanced Format drive (W7 64bit) to a new hard drive (Seagate) that was AF, the software I used supposedly does not support 4k very well (Todo Backup Free 3.5).

  1. Is there a Windows utility to check alignment? I know of the Western Digital tool but not sure if it works on Seagate brand drives.

  2. If the partitions are not aligned, Am I better to clean install W7 64bit or do the partition alignment procedure? If so, Why?

It seems to be running fine so far. From what I have read Seagate drives use "Smart Align" technology to help with misaligned partitions on the fly, might explain why it runs well for me, but would still like to have the partitions aligned properly.

EDIT: Here is the diskpart output for my disk partitions

DISKPART> list partition

  Partition ###  Type              Size     Offset
  -------------  ----------------  -------  -------
  Partition 1    Primary            188 MB    31 KB

  Partition 2    Primary            698 GB   188 MB
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I used paragon align utitlity. there is a big difference between 4k sectors presented to the system as 512b sectors , and 4K used on the disk and presented to the system itself. win7, paragon and other partition software aligns properly as needed. some other free partition programs do not. in my uses I have not seen these large changes in speed via alignment, when i went through the bs to do it. but most of my data often crosses many clusters. I really cant be sure that the software even knew what it was doing :-) why would it take 2Meg shift for 32K clusters, and same ~2M shift for 4k ? – Psycogeek Jan 8 '12 at 7:54
@Psychogeek: Hint, 32 and 4 have a common factor. – surfasb Jan 8 '12 at 11:58
@Surfasb thanks, so whats with the quantity? if they only need to keep from starting the cluster arrangment in the center of a sector, then why a whole meg or 2? And what was the point of aligning the end of the partition also? there would be zero effect that the last chunk was not all aligned perfect? – Psycogeek Jan 8 '12 at 12:35
up vote 6 down vote accepted

You can use diskpart. Use an elevated command prompt and list disk. Then select disk 0 or whatever disk it is.

list partition. The last column should be the partition offsets.


I've added a different method for more accuracy. In general, the diskpart method will work if you see 1024 in the offset. But the numbers are rounded.

Enter this command for a more accurate display:

wmic partition get Name, StartingOffset

Take the offsets and divide them by 4096. There should be no remainder. If there is a remainder, then your offsets are wrong and your clusters are not ending the same boundary as your 4K sectors.

BTW, the 31KB on your first partition is the typical offset a non AF aware OS will set the offset as.


Question 2

Realigning the partition surmounts to moving a partition. If you just correct the offset, it amounts to the same as a full reinstall. As always, you run the risk of losing your data if something goes haywire. Reinstall is a bit much, but it also solves the issue.

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I would not know what looks right or not. I will post the output. – Moab Jan 8 '12 at 17:02
check my edit... – Moab Jan 8 '12 at 17:05
The offsets are suppose to be divisible by 4096. – surfasb Jan 9 '12 at 0:36
I added a more accurate display. But a little math will tell you that the offset is wrong. – surfasb Jan 9 '12 at 0:41
@Moab: To realign the partition, you are going to have to realign every file cluster. That's the whole point. – surfasb Jan 10 '12 at 9:39

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