What is 4K alignment in the hard drive

In fact, "4K alignment" is associated with a partitioning technique called "advanced format". "Advanced Format" is the international hard disk equipment and materials Association for the new data structure format adopted by the name. This is mainly due to the current expansion of hard disk capacity, so that the previously defined 512 bytes per sector is no longer reasonable, so that each sector 512 bytes to 4,096 bytes per sector, which is now often said "4K sector."

In fact, the definition of 512 bytes per sector originated from the beginning of computer development, so at that time the hard disk capacity cut into 512 bytes per block is balanced with file management and storage. And now the mainstream hard disk capacity has climbed to 1TB or even higher, and the old standard to manage the current super large capacity of the hard disk is not only cumbersome, but also reduce efficiency, so the capacity of a single sector to enhance the inevitable.

4K not aligned, the consequences are very serious after understanding the definition of "4K sector", it is easy to understand what is called "4K alignment". The so-called "4K alignment" is consistent with the "4K sector" definition of the formatted hard disk, and according to the "4K sector" rules write data. Then if there is "4K alignment" one said there must be "4K alignment". Why is "4K" not aligned? This is because in the previous specification of ntfs6.x, the write point of the data is exactly between two 4K sectors, which means that even a minimum amount of data is written to two 4K sectors, which can have a significant impact on both write speed and read speed. For this reason, "4K misaligned" situation, we must modify the "4K alignment" to the line, otherwise, for solid-state hard disk, not only will greatly reduce the data write and read speed, but also will cause the solid-state hard disk unnecessary write times.

If you show ok here, then 4K is aligned, and if it's bad then it means 4K is not aligned.

How to do 4K alignment?

Finally, say how to do "4K alignment". If you use the system's own tool to format the WINDOWS7, the formatted partition will be "4K aligned" by default, and the user no longer has to make any settings. If you are still using the XP operating system, then the "4K alignment" needs to rely on Third-party tools. For example, using the "Diskgenius" software can be manually "aligned to the following sectors of the integer multiple" sector number select 8 or more to achieve "4K alignment."

XP Select "2048" to achieve 4K alignment

Of course, "4K alignment", not all users need to tangle. After all, it takes a little bit of technology and a little risk of data loss to turn a "4K misaligned" hard drive into "4K alignment". Therefore, it is recommended that if the hard disk as a storage disk rather than the system disk, "4K" is not important, at the same time for ordinary mechanical hard disk users, limited by 4K read performance, "4K" is not so important to align. And if it is a solid-state hard disk users, "4K" must be aligned!

4K sector alignment exactly what is aligned with.

Disk partitions are formatted to a file system, such as NTFS,FAT32,EXT4, and so on. When Windows file systems store files in clusters, the NTFS cluster size defaults to 4K, and 4K sector alignment refers to the 4K sector of the hard disk that corresponds to the 4K cluster one by one.

Why is there a situation that is not aligned?

Because the previous system or zoning software did not consider this situation, is the starting position of the first partition with the 64th sector of the 512-byte sector disk, and this position is exactly the last position of the eighth sector on the disk in the 4K sector, resulting in the scenario as shown:

If you are storing the data through the system at number 4th, you need to change the location of 1 and 2nd, which means that you need to do twice times the original work to save a data. If the data is stored at number 5th, and the first half of the number 2nd is stored, then the data needs to be moved out to 4K to be stored in the 2nd position, that is, the process of "read-Modify-write" three processes, obviously time-consuming and trouble. It is not affected to read continuous clusters under this process, but it is also affected when the data storage is discontinuous.