How Many Bad Sectors Are Acceptable?

Introduction to Disk Sector

In the computer field, the term – sector – originates from the physical structure of HDDs. As we all know, in an HDD, data is stored on platters. The platter is divided into concentric circles, which are the tracks.

The platter is divided into multiple geometric sectors of the same specifications, starting from its center. The part where the geometric sector and the track overlap is the disk sector. Note that in modern disks, every sector has the same size.

What Is a Bad Sector?

A sector is the smallest unit for reading and writing data on a disk, but it can be damaged for various reasons. Once it becomes damaged, it is inaccessible and all information stored on that sector is lost.

Bad sectors can be “soft” (logical) or “hard” (hardware, physical), depending on what is making the sector inaccessible. In case of power loss, bit rot (more likely on floppy disks), or firmware issues, logical bad sectors may occur. Then, you can fix them by reformatting the drive.

Physical bad sectors may occur due to head crash, wear-and-tear, physical shock, or dust intrusion. They cannot be restored.

Signs That Indicate Bad Sectors

In most cases, when we say bad sectors, we mean the physical bad sectors. After reading the above content, you can know that bad sectors are a threat to information security.

The common signs and symptoms that indicate bad sectors in a hard drive are as follows:

1. Strange noises on booting, especially at the time of reading/writing and hard disk drive opening.
2. Error messages like “Files become corrupt while running a program or reading a file”.
3. System is consuming a long time to run a program or read a file.
4. System shows blue screens frequently.
5. When your system shows a warning message such as a “General error in reading drive C” or “Sector not found”, even though it is not attacked by a virus.
6. When Windows fails to complete the hard disk drive format, including the Quick Format and Full Format.
7. The system auto-scans errors in the hard drive every time when the computer boots up.

How to Scan a Disk for Bad Sectors

When these issues occur, you may guess if there are bad sectors on the hard drive. Then, you can use tools like MiniTool Partition Wizard, Hard Disk Utility, CrystalDiskInfo, and so on, to check that.

Here, I will show you how to use MiniTool Partition Wizard to scan the hard drive for bad sectors for free. This tool can not only find bad sectors, but also partition hard drive, clone hard drive, recover hard drive data, etc.

MiniTool Partition Wizard FreeClick to Download100%Clean & Safe

Step 1: Download, install, and launch MiniTool Partition Wizard. Right-click the disk and choose Surface Test.

Step 2: On the pop-up window, click Start Now. If bad sectors are found, they will be marked with the red color. 

How Many Bad Sectors Are Too Many?

If you run software to detect bad sectors, it will tell you the number of the bad sectors are on your hard drive. Then, how many bad sectors are too many? Or another word, how many bad sectors are acceptable?

Some people may think none of bad sectors are acceptable. This idea is wrong to some extent because each hard disk has a certain number of bad sectors recorded before leaving the factory, and some even have thousands or tens of thousands of bad sectors. In comparison, one or two bad sectors discovered by users is not a problem.

Then, how many bad sectors are acceptable? We can’t tell you a fixed number because it varies according to the specific disk size. In addition, bad sectors on different hard drives may increase at different rates.

In general, we recommend that if you run disk utilities regularly and notice bad sector counts increasing dramatically, you should back up the hard drive or replace it.

What to Do If Too Many Bad Sectors Are Detected?

Some people may run the WD Data Lifeguard Diagnostic to test their hard drives and this software tells them 08-too many bad sectors detected. Of course, other bad sector checking software will also report errors similar 08-too many bad sectors detected.

When this issue occurs, what you should do is to back up the hard drive. Then, buy a new hard drive to replace it. To back up the disk, you can also use MiniTool Partition Wizard. Here is the guide:

MiniTool Partition Wizard DemoClick to Download100%Clean & Safe

Step 1: Connect an external hard drive to your PC. Download, install, and launch MiniTool Partition Wizard. Then, click Copy Disk Wizard.

Step 2: Click Next. Select the disk you want to copy and click Next. Select the external hard drive as the target disk and click Next. You are warned that all data on the target disk will be destroyed. Click Yes to continue.

Step 3: Review the changes. You can change the disk layout there. You can also keep all as the default value and click Next.

Step 4: Click Finish. Then, click Apply to execute the pending operation.

How many bad sectors are too many? If you wonder about this question, this post can help you.Click to Tweet

Bottom Line

Do you have other opinions on the bad sectors? Share them with us in the following comment zone. In addition, if you encounter problems when using MiniTool Partition Wizard, please feel free to contact us via [email protected]. We will get back to you as soon as possible.