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)
Currently, all IDE/SATA hard drives expose either 512B or 4KB sized blocks (depending on make and model) for read/write operations. Those are the only two options available (shame, because I can imagine other LBA sizes being very advantageous).
When an OS reads/writes to a hard drive, it has to manage the difference between the file system's sector size and the hard drive's LBA size. For a 512B hard drive, writing a 4K NTFS sector requires 8 x 512B writes. You can see how a 4K drive might perform better given that the same operation would only take 1 x 4K write.
The way SSDs do things internally varies by make and model. Page sizes can be different.
Best Answer
In order to know this, you should check how wear leveling works.
Where do writes to a specific partition go?
In both dynamic and static wear leveling, a map is used to link Logical Block Addresses (LBAs) to the SSD memory. Thus, any write that you do to the SSD can get placed anywhere on the SSD...
You can see it as some kind of extra interface between your OS and your SSD, which just translates locations into other locations. Towards the OS there is just no difference. However, if you were able to look past the map you would see a lot of data scattered around, like a really fragmented disk!
What will prevent that I write more than the partition can contain?
The OS does this, as a partition only has a limited amount of LBAs.