ST4000NM000A vs ST4000NM002A : New 512e Low cap drives

Seagate has introduced the 512e drives in lower capacities like 2TB, 4TB, and 6TB drives, these drives were earlier available only in 512n format. 

Formats - 4K Advanced Format, 512n and 512e

Traditional drives have logical block sectors of 512 bytes- so at a time, 512 bytes can be read and written. This scheme worked for a very long time and works with all the operating systems and applications. 

However, the 512-byte block presents a challenge - the number of blocks becomes very high for the high capacity drives, making error correction more challenging, and a new format was introduced - the 4096 bytes, AKA 4K or Advanced Format - AF. 

The 4K format means that 4,096 bytes can be read and written at a time, this increases efficiency and error correction. 

But what about the OS and application which are not 4K aware - industry found a way to have a 4K drive emulate the 512 bytes sector and called it a 512e drive. So the hardware platform is 4K, but it's made to look and behave like a 512 drive for compatibility. 

• 4K drives are all 4K native. They read and write in block sizes of 4,096 bytes, but the application and OS must be 4K aware
• 512n drives nativly write in 512-byte sectors. 
• 512e drives are 4K by hardware design but appear as 512n to the OS. 

New 512e Low cap drives in Seagate

This table shows the new drives in 512e format and the corresponding drives in 512n format. Both the drives will appear as 512n to your application so there won't be any difference.