Hard vs Soft Bad Sectors in HDD: Different Causes and Solutions

Bad sectors are tiny clusters that cannot be read in hard disk drive (HDD). They can be divided into two types. One is hard bad sectors, and the other is soft bad sectors. This article will expose the different causes and solutions of the two types.

It is known that hard disk drive (HDD) is vulnerable due to its mechanical parts. Among all hard drive issues, bad sector is admittedly common. Hard disk drive is divided into millions of sectors. Bad sector refers to a sector that is unreadable in hard drive. In addition, it can be separated into two kinds. One is hard bad sector, and the other is soft bad sector. Different types of bad sectors can result from different reasons and should be dealt with by different means. In the followings, we will discuss about them in detail.

Hard vs Soft Bad Sectors in HDD: Different Causes and Solutions

Hard Bad Sectors

Hard bad sectors, also known as physical bad sectors, are the clusters of storage in hard drive, which are physical damaged. It can be treated as a kind of physical damages.


Physical bad sectors can occur from many causes. For instance, they may develop when the drive are manufactured. As we all know, a drive has millions of sectors. During manufacturing, it is an arduous and cumbersome to check bad sectors. In addition, such bad sectors can be caused due to users errors. If you dropped your drive heavily or exposed it to extreme heat, or some dust was accumulated in the drive, bad sectors may be created.


It is sad that such bad sectors cannot be repaired. That is to say, the data stored in the hard bad sectors will be corrupt and lost, such as damaged PST file. It can’t be recovered absolutely. Hence, please use your hard drive with care.

Soft Bad Sectors

Soft bad sectors, also called as logical bad sectors, are the clusters in a hard drive, which seem not being working properly. More specifically, when your computer operating system tries to read drive data from such a sector, it may find that error correcting code (ECC) don’t match the sector contents. Thereby, the sector cannot be read.


Generally, logical bad sectors are led by software issues. For example, in case of power outage, your PC shuts down abruptly, and then the hard drive will shut off even though it’s writing to a sector. In this scenario, the sector may be subject to logical problems.


Fortunately, unlike hard bad sectors, soft bad sectors can be repaired. And most systems provide inbuilt disk repair tools. For instance, on Windows, it is CHKDSK. And on Mac, it is Disk Utility. Both of them play great roles in repairing soft bad sectors. Generally, after fixing, the sector can be read and written as normal.

Author Introduction:

Shirley Zhang is a data recovery expert in DataNumen, Inc., which is the world leader in data recovery technologies, including recover mdf and outlook repair software products. For more information visit www.datanumen.com

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