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I have an external drive. Inside is a Seagate Barracuda (ST3000DM001 (Datasheet)). With its original controller (Intenso) its working fine. But with another controller (AS-Media) its partition layout is wrong and nothing can be read by Windows (Win7 Ent. SP1). I have read contradictory things on 4K alignment (4k-sector-hard-drives, 4K disk compatibility update). Can someone please confirm the following statements in quotation marks (based on the inserted image made with Windows 10 Powershell: Get-Disk | Format-List).

Intenso is 4Kn. AS-Media is 512e ?!

"The drive is 4K as for all drives above 2TB. The Intenso controller does no emulation and thus the drive is visible as a 4Kn drive to the operating system. The AS-Media controller does emulation and therefore the drive is visible as a 512e drive to the operating system."

Windows 7

wmic diskdrive get bytespersector,model

reports with Intenso:

4096 Intenso USB 3.0 Device USB Device

reports with AS-Media:

512 ASMT 2115 USB Device


A similar question can be found here.

UPDATE

Windows 10 build 1607++ and Windows 7 SP1 with KB 982018 should be able to correctly report if the drive is 4Kn, 512n or 512e. As you can see from the screenshot both operating systems report 4Kn (4096/4096) for the external drive (H: in Win10 and I: in Win7). If this drive emulates the advanced format 512e (512/4096) it would look like the boot partition (C:) in the screenshot. Why should one not trust this output? What would be the rational to fake the LogicalSectorSize?

Windows 7 and 10 reporting 4096/4096

Update 2

All my misconception (read "contradictory" above) resulted from the problem that there are possibly 2 emulations. 1st emulation (512e) between drive and host interface (when directly connected to internal SATA port). 2nd emulation ("4Ke") between USB and host interface (for external drives) where the USB interface is a man in the middle, delegating between drive and host. Possibly 2 emulations because it obviously depends on the controller. With Intenso ("4Ke") there is a 2nd emulation and with AS-Media ("Non-4Ke") there is not a 2nd emulation.

  • No, actually the Intenso controller does emulation. That’s because there is virtually no consumer-grade 4Kn drives available as of yet. – Daniel B Nov 26 '17 at 16:21
  • This makes sense regarding the fact that it is working with Windows 7 since this OS can't handle 4Kn. But why does it report to be 4Kn in Windows 10? If it is emulated (512e) why doesn't it work with the AS Media controller? – dkeck Nov 26 '17 at 16:42
  • 4kn is native 4k sectors, which means if it’s reported as being 4K then it’s emulating that support but actually 512 enchanted. Furthermore Windows 7 doesn’t even support 4K native, so your drive couldn’t use that mode, given your OS – Ramhound Nov 26 '17 at 17:58
  • Please see the update. If this was emulated (512/4096) why does the AS-Media controller then fail to work? Why is 4Kn (4096/4096) reported on both operating systems? – dkeck Nov 26 '17 at 20:21
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I have overlooked a monster: Backward compatibility!

enter image description here


So the correct statement is:

"The drive is 512e. The Intenso controller does emulation (as Daniel B stated) and thus the controller makes the drive visible as a "4Ke" drive to the operating system. The AS-Media controller does no emulation and therefore the drive is visible as a 512e drive to the operating system."


So I can also answer my own questions.

What would be the rational to fake the LogicalSectorSize?

Answer: Make drives over 2TB available for systems with MBR support only. Windows XP was still a giant 6 years ago.

Why does the AS-Media controller then fail to work?

Answer: Misalignment (by factor 8).

Why is 4Kn (4096/4096) reported on both operating systems?

Answer: There is no difference in representing a 4Kn drive or "4Ke" drive (=512e drive + "4Ke controller").


Summary:

512e drives ("1st emulation") allow you to use old drivers with new disks (since 2009!). "4Ke controllers" ("2nd emulation") allow you to use legacy MBR with huge disks (cf. Update 2 in question).


A side note on encryption: Using TrueCrypt or some similar tools where disks have no format (RAW, uninitialized, no file system) it is important to know that enclosures come with "4Ke" or even their own encryption(German).


The solution for me will be slowly transitioning from "4Ke" to "Non-4Ke" by reformatting all drives.

I consider this issue a far worse problem than having told people in the first place that drives beyond 2TB wont work with their XP installation. E.g. Paragon and GPT could workaround it and maybe even free solutions exist. All the non-tech-savvy guys that will transition due to corrupt USB controllers (I consider this life span far shorter than the hard drive itself) will find themselves confronted with the question if their data has been lost with no help at hand.


Since I didn't search if there is some good list out there right now. I add some controllers here to both classes. Feel free to modify.

"4Ke" - logical/physical = 4096/4096 - identical to 4Kn :(

Intenso (e.g. Memory Center)
LogiLink QP0020 (thanks Thomas Weller)

"Non-4Ke" - logical/physical = 512/4096 -

AS-Media (e.g. Anker)
inateck FD2002 (thanks Thomas Weller)

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