My understanding was that hard drive manufacturers had announced the move to 4K sectors back in 2010, and 4K sector support has been present in operating systems since Windows Vista. Yet I just checked my brand new Samsung 980 PRO 2TB SSD and it reports 4K physical sectors but an emulated 512 byte interface. Same with my 8TB Seagate. I find it odd that its been more than 10 years and drives are still presenting themselves to the OS as if they are 512 byte sectors.

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1 Answer 1


The reason hard drive manufacturers emulate a sector with a length of 512 byte is to increase compatibility - especially for the use as a boot drive.

Loads of software products and even operating systems have hardcoded 512 as a sector and do not query the drive.

They fail when handling drives with a sector size different from 512 bytes.

Misalignment - as others pretend - only results in performance degradation and additional hard drive wear but is no reason for a harddrive to show virtual sectors with a size of 512 bytes. It is rather the opposite: The effort to maintain compatibility by showing sectors of 512 bytes to the world outside of the hard drive which then have to assigned to internal sectors of 4096 byte by the firmware of the hardware causes alignment problems.

  • 2
    I guess I am just surprised that 11 years on from its announcement aggressive backwards compatibility has prevented it from replacing the old standard, despite the fact that modern operating system have been ready for it for years.
    – Chris_F
    Aug 6, 2021 at 12:49

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