Run wmic partition get BlockSize, StartingOffset, Name, Index from a Windows Command Prompt. The output looks like:
BlockSize Index Name StartingOffset
512 0 Disk #0, Partition #0 1048576
512 1 Disk #0, Partition #1 105906176
512 0 Disk #1, Partition #0 32256
Where block size is the drive's sector size. It unfortunately doesn't list the drive letter.
Also as I understand the article, the drive will still list that it has 512 byte sectors even though internally it uses 4kb sectors. So the only way may be to get the drive's spec sheet.
Many Western Digital external USB drives over 2 TB (including at least some My Book, My Book Essential, Elements, and Easystore drives) can be configured for either 512 byte logical sectors or 4096 byte logical sectors using the WD Quick Formatter tool. When configured for 4096 byte logical sectors, the USB-to-SATA bridge in the enclosure does a translation between 512 byte logical sectors at the SATA interface to the internal drive and 4096 byte logical sectors at the USB interface to the host computer.
With 512 byte logical sectors, an MBR partition table could only use up to 2 TB of a drive. That's because MBR table entries are 32 bits with a max of 2^32 or 4,294,967,296 sectors. 2^32 sectors x 512 bytes/sector is 2 TB. With 4096 byte logical sectors, an MBR partition cable can use up to 16 TB of a drive. (2^32 sectors x 4096 bytes/sector is 16 TB) Windows XP only supports MBR partition tables, and so 4096 byte logical sectors are the only way to use all of the space on a drive over 2 TB in Windows XP. The newer GPT partition table format supported in Windows Vista and later does not have the 32-bit limitation, and can support disks larger than 2 TB regardless of the sector size.
The WD Quick Formatter tool (version 2.0.0.65 available for download as of this writing) can enable or disable the sector size translation. This version of the tool does not work correctly under Windows XP, so I recommend running the tool in Windows 7 or later. When run in Windows 7, or in later version of Windows but with Windows 7 compatibility mode, the tool will present two configuration options on the "Format your WD external drive" screen:
- XP Compatible: This option configures the drive for 4096 byte logical sectors, and creates an MBR partition table.
- Most Compatible (Vista or later required): This option configures the drive for 512 byte logical sectors, and creates a GPT partition table.
Both options also create a single partition filling the entire drive, and quick format it in NTFS.
If you run the tool in Windows 8 or later without putting it in Windows 7 compatibility mode, the tool will not present a compatibility option on the formatting screen and it will format in the "most compatible" mode (512 byte logical sectors).
WD Quick Formatter 2.0.0.65 doesn't work correctly in Windows XP: it successfully configures 4096 byte logical sectors, but fails to format correctly. Another tool can subsequently be used to partition and format the drive.
WD Quick Formatter 1.2.0.10 works correctly in Windows XP, but is not available for download from Western Digital anymore.
When the target drive is configured for the same logical sector size as the source, you can copy to it using dd and the copy will work without any need to alter the partition table.
I can confirm that these Western Digital external USB drives can be configured for XP compatibility:
Easystore 14 TB (WDBCKA0140HBK)
Easystore 12 TB (WDBCKA0120HBK)
Easystore 8 TB (WDBCKA0080HBK)
My Book Essential 1140, 3 TB (WDBACW0030HBK)
Elements 1021, 3 TB (WDBAAU0030HBK)
Best Answer
Bar none, this is the best article I have read on the topic:
http://www.anandtech.com/show/2888
In a nutshell, to answer your questions:
The primary advantage is more efficient use of the raw storage space. The necessary ECC calculations were starting to provide diminishing returns using 512 byte sectors, but they can be done much more efficiently on larger sector sizes.
The real advantage is that drives larger than 2TB will be more affordable and reliable sooner than without the transition. The same idea holds for smaller drives too, but the returns aren't as dramatic. There are some theoretical advantages to having the sector size map to the common allocation size in a volume (4K for NTFS is about as common as dirt) and memory pages are generally 4K in size as well (makes the pagefile/swap happy).
Today - the only thing you should care about it is probably not getting one. There are still a few kinks that are being worked out that if you aren't aware of might cause you grief. Windows XP support is one, the drives lying about their geometry is another.
It has been in transition for many years already, but consumer drives are just starting to appear on the market.
You probably won't experience a problem with Windows 7 or Vista, but any of the older Microsoft OS's might cause you grief. There is compatibility built in, but because of sector alignment issues it might cause performance degradation.
Read the article, brush up on your math, and then read it again. Really it is a good thing and will enable the storage industry to continue forward more rapidly.