View source for Hard Drive Logical Block Format Migration to 4K- Alignment

Traditionally the logical block format size know as a sector, had remained constant over the years.  Around 2010, hard drive companies began migrating away from the legacy sector size of 512 bytes to a larger sector size of 4096 bytes (4K).  

A logical sector is the minimum operating unit that hard drive receives read and write commands. Many aspects of modern computer systems still have design assumptions based on a legacy sector size of 512 bytes.  The bad side to this is the limitations it imposes on error correction efficiency.  The small 512-byte sector has consumed a smaller and smaller amount of space on the hard drive surface as areal densities have increased. This is a problem in the context of error correction and the risk of media defects.

Solid State Drives is more complicated to implement, as it has "pages" and "blocks", which can be simply regarded as logical sectors and physical sectors.  SSD has a higher demand for partition 4K alignment. If it is not aligned, extra actions increase and read/write performance degrades.  It is important to use 4K alignment for your SSD.