How can I determine the sector size in windows?

Question

How can I determine the Physical Sector Size (e.g. if i have an Advanced Format drive with 4,096 byte sectors rather than the legacy 512 byte sectors) in Windows 7?

I know that by clicking on a file and get properties we can find out the NTFS Cluster Size, but that's not the same as the hard-drive's sector size.

Note: We ask about Windows 7 because it (and Windows Vista SP1) understand the existence of 4096 Advanced Format hard drives.

Brinker

I'm going to update this for Windows 10, since this is the first article that comes up in my search: Use Powershell, "Get-Disk | Format-List" (however, it doesn't show all of my disks...) – Methinks

Better update for Windows 10, "Get-PhysicalDisk | select physicalsectorsize, friendlyname". Shows all my physical disks and their sector size properly. – Methinks

Answer 1

You want fsutil. Make sure you run Command Prompt as Admin.

C:\Windows\system32>fsutil fsinfo ntfsinfo c:
NTFS Volume Serial Number :       0xf4ca5d7cca5d3c54
Version :                         3.1
Number Sectors :                  0x00000000378fd7ff
Total Clusters :                  0x0000000006f1faff
Free Clusters  :                  0x00000000000e8821
Total Reserved :                  0x0000000000000910
Bytes Per Sector  :               512
Bytes Per Physical Sector :       512
Bytes Per Cluster :               4096
Bytes Per FileRecord Segment    : 1024
Clusters Per FileRecord Segment : 0
Mft Valid Data Length :           0x00000000196c0000
Mft Start Lcn  :                  0x00000000000c0000
Mft2 Start Lcn :                  0x000000000097ffff
Mft Zone Start :                  0x000000000051f920
Mft Zone End   :                  0x000000000051f9a0
RM Identifier:        0652C3D3-7AA9-11DA-ACAC-C80AA9F2FF32

Cooncan

When property Bytes Per Physical Sector: <Not Supported> this means 512 – Sharl

@Sharl Do you have a source for that? – Antirrhinum

What's 'FileRecord Segment' ? Is it the extra storage for files' metadata? – Slavophile

Answer 2

Windows 10 update:

There is now a sectorInfo sub-command which may provide better information:

C:\>fsutil fsinfo sectorInfo C:

LogicalBytesPerSector :                                 512
PhysicalBytesPerSectorForAtomicity :                    4096
PhysicalBytesPerSectorForPerformance :                  4096
FileSystemEffectivePhysicalBytesPerSectorForAtomicity : 4096
Device Alignment :                                      Aligned (0x000)
Partition alignment on device :                         Aligned (0x000)
Performs Normal Seeks
Trim Not Supported

Dorkus

Works on 2012 R2 – Mystique

Not available on Windows 7 Ultimate. – Antirrhinum

Answer 3

i wanted to expand on Chris Gessler's answer, and note that there is no known way to get the Physical sector of a drive using Windows Management Instrumentation (WMI), e.g. wmic.

Given that i have an Advanced Format drive (i.e. it uses 4,096 bytes per sector rather than 512):

C:\Windows\system32>fsutil fsinfo ntfsinfo d:
NTFS Volume Serial Number :       0xa016d8a616d87eaa
Version :                         3.1
Number Sectors :                  0x00000000747057ff
Total Clusters :                  0x000000000e8e0aff
Free Clusters  :                  0x000000000e7b2813
Total Reserved :                  0x0000000000000000
Bytes Per Sector  :               512
Bytes Per Physical Sector :       4096

Neither WMI's DiskDrive:

wmic:root\cli>diskdrive
Availability  BytesPerSector  Capabilities  CapabilityDescriptions                                       Caption
              512             {3, 4, 10}    {"Random Access", "Supports Writing", "SMART Notification"}  ST1000DM003-9YN162 ATA Device

 

nor Partition:

wmic:root\cli>partition get BlockSize, StartingOffset, Name, Index
BlockSize  Index  Name                   StartingOffset
512        0      Disk #0, Partition #0  1048576

can report the underlying physical sector size. It makes sense when you realize they both report the sector size that Windows is using. It is 512 bytes per sector - the drive just happens to be different inside.

That's because only Windows 8 supports use of 4k sectors. Windows 7 understands that the drive might be 4k, and works to align it's 4k Clusters with the hard-drive's underlying 4k Sectors.

Update

wmic diskdrive now does show physical bytes per sector in Bytes per Sector:

C:\Windows\system32>wmic
wmic:root\cli>diskdrive
Availability  BytesPerSector  Capabilities  CapabilityDescriptions                                       
              4096            {3, 4}        {"Random Access", "Supports Writing"}                        

While wmic partition continues to be wrong.

Windows 10.0.19041.804

Epicenter

This answer is severely outdated. These utilities now show the logical (emulated, almost always 512) and physical (real, almost always 4096) sector sizes. See the other answers. – Sack

Answer 4

1. Run msinfo32 in command line that should popup a GUI window called "System Information"
2. In the left pane select "System Summary->Components->Storage->Disks". This should load info of all drives in the right pane
3. Find your desired drive and check the value for "Bytes/Sector". it should say "Bytes/Sector 4096"

Barnard

Answer 5

If you want to have it programmatically, you need to send IOCTL_DISK_GET_DRIVE_GEOMETRY_EX and use Geometry.BytesPerSector from DISK_GEOMETRY_EX structure

Sherlock

That reports only the logical sector size. Getting a STORAGE_ACCESS_ALIGNMENT_DESCRIPTOR struct from passing IOCTL_STORAGE_QUERY_PROPERTY to DeviceIoControl will get both the logical and physical sector sizes. The only shortcoming is that it doesn't work for external hard drisks - DeviceIoControl returns ERROR_INVALID_FUNCTION (at least, I haven't found a way to make it work for external hard disks). – Siphonophore

Answer 6

You can use wmic from the command line:

C:\Windows\System32\wmic partition get BlockSize, StartingOffset, Name, Index

BlockSize  Index  Name                   StartingOffset
512        0      Disk #0, Partition #0  32256
512        1      Disk #0, Partition #1  370195176960

The BlockSize is the sector size of the drive.

Coronel

That BlockSize is the logical sector size, and not the physical size that fsutil fsinfo ntfsinfo c: reports. Source: i have a 4,096 AF drive that fsutil reports as 4096 and BlockSize reports as 512. – Epicenter

Second the above, this only reports logical sector size. fsutil reports correctly. – Antirrhinum

Answer 7

Powershell:

$wql = "SELECT Label, Blocksize, Name FROM Win32_Volume WHERE FileSystem='NTFS'"
Get-WmiObject -Query $wql -ComputerName '.' | Select-Object Label, Blocksize, Name

Output example:

Label            Blocksize Name
-----            --------- ----
OSDisk                4096 C:\
Windows RE Tools      4096 \\?\Volume{b042c778-cd66-4381-9312-3f4311321675}\
PS C:\>

Crites

Explain this... msinfo32 reports all as 512, this reports all as 4096, I KNOW I have both, as I can't set up a mirror, but I don't know which disk is which... Also, this only shows the drive letter, not the disk. – Methinks

Answer 8

Recent powershell versions have a Get-Volume

Get-Volume  | Format-Table DriveLetter, FileSystemLabel, AllocationUnitSize

Greenway

Answer 9

If you really want to have it programmatically, you need to send IOCTL_STORAGE_QUERY_PROPERTY providing STORAGE_PROPERTY_QUERY with PropertyId set to StorageAccessAlignmentProperty. This gives both physical and logical sector sizes.

Note: this only works on Windows Vista and higher.

Fredi