Why align partitions

In addition, SSD has to execute data erasing operation before writing data, as data cannot be written to blocks that already contain data. Hence, SSD has a higher demand for partition 4K alignment.

A disk should be partitioned and formatted prior to storing data. Simply put, a partition is a large area of contiguous sectors divided from disk. Formatting works to plan the usage of sectors in the partition, for instance, how to arrange the storage of file data, where to store file attributes, how to store directory structure, etc.

A partition can be used to store data after being formatted. Formatting process groups all sectors in the partition from beginning to end, dividing them into fixed-size clusters and numbering clusters in sequence. Each cluster can fixedly contain one or more sectors and sector count is always 2 to the power of n. Once a partition gets formatted, cluster will be the smallest unit to read or write action. File information such as data, attributes and so on is stored to clusters. When partitioning a disk, partitions are divided in the unit of logical sectors and a partition can start from any numbered logical sectors.

If the starting position of a partition is not aligned to the edge of a certain physical sector, after formatting, all clusters won't align to the edge of physical sector, either. As shown in the picture below, each physical sector consists of 4 logical sectors and partition starts from sector No. After formatting, each cluster occupies 4 logical sectors and none of these clusters are aligned to the edge of physical sector, that is, each cluster spans 2 physical sectors.

Since disk always reads and writes in the unit of physical sectors, in this case, it has to read an additional physical sector when a cluster is to be read. For instance, to read data on cluster No. Similarly, the write operation to cluster is same process. Let's take a look at an aligned example. As shown below, partition starts from sector No.

After formatting, each cluster contains 4 logical sectors and all clusters align to the edge of physical sectora. Obviously, this is exactly what we need. As shown in the two examples above, formatting process will align each cluster to the edge of physical sector as long as partition's starting position is aligned to the edge of physical sector.

Thus, it is quite easy to get 4K alignment. How to check physical sector size? Physical sector size on your disk should be aware in order to achieve 4K alignment during disk partitioning.

Launch DiskGenius and select the disk from the main interface and you can view disk parameters in details. As shown in the picture below, the physical sector size of selected disk is bytes. It contains 8 logical sectors via simple calculation. If not, you need to realign it.

In the pop-up window, you could set the sector of partition to align. We advise SSD users to align partition in sector. You also can use the default size. Partition Alignment. Partition alignment Refers of the starting location of the logical block LBA or sector partition created by the operating system. If it is, the partition is correctly aligned. That means the sectors are correctly aligned. If we did the math and found a decimal remainder e.

If you find that your partitions are incorrectly aligned, you can fix them and hopefully get a nice speed boost. Quite a few partition managers can realign your partitions for you. However, this often involves some complex fiddling. Image Credit: Kal Hendry.

Browse All iPhone Articles Browse All Mac Articles Do I need one? Browse All Android Articles Browse All Smart Home Articles Customize the Taskbar in Windows Browse All Microsoft Office Articles What Is svchost. Browse All Privacy and Security Articles Browse All Linux Articles Browse All Buying Guides.

Best Portable Monitors. At this time, just click on Apply button to perform this operation. But i f the selected partition is already aligned, users will get the information below. After that, partition alignment is completed via MiniTool Partition Wizard.