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How to Format Block Size to 512 (or Other Sizes) in Windows

HardDrive

Abstract

Block sizes on hard drives refer to the smallest unit of data that the drive can read or write. Common block sizes are 512 bytes and 4096 bytes (4KB). These sizes are typically compatible with most operating systems, including Windows. However, some enterprise-grade drives use a 520-byte block size to store additional metadata for data integrity and error correction. This 520-byte block size is not compatible with Windows because Windows expects the standard 512-byte or 4KB block sizes for proper data alignment and access. As a result, drives with a 520-byte block size need to be reformatted to a 512-byte block size to be used effectively with Windows systems.

Solution

To resolve this, you can use a Windows tool called sg3_utils. Follow the steps below to reformat the block size of your drives.

Step-by-Step Guide

  1. Download and Unzip sg3_utils

    • Visit the following link to download the tool: sg3_utils.
    • Scroll down to find the latest version and unzip it to a convenient location on your computer.

    sg3_itils

  2. Open Command Prompt as Administrator

    • Open the Windows search bar, type "Command Prompt," right-click on it, and select "Run as administrator."

  3. Navigate to the sg3_utils Directory

    • Use the cd command to navigate to the folder where you unzipped sg3_utils.
    • Example command (adjust according to your actual directory path): 
      cd C:\Users\Asus 2600k\Desktop\sg3_utils148mingw64\msys64\home\Douglas_Gilbert\sg3_utils-1.48mgw64

  4. Scan for Connected Drives

    • Once in the correct directory, type the following command to list all connected drives: 
      sg_scan
    • Identify the drive you wish to reformat from the list.

  5. Reformat the Drive

    • Use the following command to reformat the drive to a block size of 512 bytes (replace PD2 with the identifier of your target drive): 
      sg_format --format --size 512 PD2

    Warning

    • Drive Identifier: Ensure you correctly identify the drive you intend to format to avoid data loss on other drives.
    • Time Required: The formatting duration depends on the drive type and size. For instance, a 500GB SSD may take around 25 minutes to reformat.

    sg3_itils

By following these steps, you can successfully reformat your drives to a compatible block size, ensuring they work seamlessly in your setup.