Difference between MBR and GPT!


We have often come across the word MBR or GPT.  If you’re installing Windows 8 / Windows 8, you’ll get an option asking you if you want the new partition as GPT or as MBR? What is GPT partition or MBR partition and how will it affect my hard disks? What if I choose MBR? Will it slow down my hard-disk?  What is the difference between MBR and GPT? In this post we’ll discuss all these questions and show you how to change a MBR partition to GPT.

MBR Partition.

MBR stands for Master Boot Record . It is one of the oldest and most used partitioning table today.  In MBR, the first sector is boot sector which consists of the information about bootloader. That means the first knows where the Operating System is located and loads it, when you start the computer.  The first sector will have a GRUB if you’re using Linux OS. MBR reads the partition containing the information about Operating System and that partition is then loaded on to the RAM.
An information table tracks partitions, the disk has been formatted into. Hence it is also referred as ‘Master Partition Table’.

The only problem with MBR is if the sector is damaged or corrupted, you need to repair the MBR using third-party softwares.

Limitation:

  1. MBR partition will work only if the disk is no more than 2 TB (2048 GB).
  2. You can only create 4 partitions. If you want more partitions you’ll have to make the last Primary partition as Extended partition which will consist the new ones.
  3. If the first sector containing the vital boot-loader information is either corrupted or overwritten, you’ll have to repair the MBR using third-party applications.
Partitioning in MBR disks

Partitioning in MBR disks

GPT Partition:

GUID Partition Table or GPT is the new type of Partition table for your hard-disks and is also a part of Unified Extensible Firmware Interface (UEFI). It uses a long unique string GUID (Globally Unique Identifies) to find each partition. These strings are random and long so that no two partitions can have the same GUID.

Advantages over MBR:

  1.  You can create any number of partitions in GPT depending on the Operating System you are using.
    Windows allows you to add upto 128 partitions when you’re using GPT.
  2. GPT can also handle disks with size of more than 2TB.
  3. Has a ‘protective MBR’ sector that protects the boot-loader information by creating copies of that sector (as a precautionary measure if the data in that sector gets corrupted) and not allowing anything to write on it. Hence, GPT header starts from the second block.
  4. MBR has no way to find if data on a disk is corrupted. GPT keeps a CRC (Cyclic Redundancy Check) to know that data is not corrupted and if it is, it tries to recover it from the disk.

How to convert Disks from MBR to GPT?

Go to Disk Management (Right-click My Computer / My PC –> Manage –> Disk Management). Make sure you have the backup of your data.

  1. Right-click on the partitions/drive and select ‘Delete Volume‘.

    Delete the Partition

    Delete the Partition

  2. Right-click on the disk and select ‘Convert to GPT disk‘.

    Right-click --> Convert to GPT disk

    Right-click –> Convert to GPT disk

  3. Once your disk is converted to GPT, if you right-click on it, you’ll find an option ‘Convert to MBR‘, which means your disk is now a GPT disk.

    Right click --> Convert to MBR

    Right click –> Convert to MBR

  4. Right-click on the partition and format it.

    Format the new partition

    Format the new partition

P.S: You need to delete the partition before converting it to GPT. When the partition is deleted, you’ll get the ‘Convert to GPT‘ option.

NOTE: Always go for GPT partitioning, if you have that option, it is more advanced and you won’t have only 4 partitions to deal with in GPT.

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