What's the Difference Between GPT Disk and MBR Disk?

When you are initializing a new hard drive with built-in Disk Manager in Windows 10, Windows 8/8.1, or Windows 7, a window pops up and asks you to choose between MBR (master boot record) and GPT (GUID partition table) disk. What's the difference between them and is there any benefit to choose one over the other?

As known to us, a brand new hard disk must be initialized before you can partition it for data storage. So when you install a new hard drive to the computer, it will first initialize the disk and ask you to choose between MBR and GPT partition style. Typically, most people would straightly click next step without knowing any of the advantages or disadvantages among MBR and GPT. However, the default setting of Windows would initialize the disk to MBR partition style or even you choose GPT, someday, you may find it not meet your needs.

The MBR, short for Master Boot Record, is an old and commonly-used disk layout. The GPT, short for Globally Unique Identifier Partition Table, is a new disk layout associated with UEFI. Firstly, you may know something about MBR like how to fix MBR, which leads you to think MBR just refer to a specific important data. Actually, MBR and GPT also determine the style of the disk between MBR and GPT. After initializing it, we can call a disk as MBR disk or GPT disk. The two different styles of disk own different schemes to manage the partitions on a disk. The differences between them are caused by the rapid development of the information age. The older scheme shows more and more disadvantages, so there introduced a new scheme to fit the changes. Once a hard disk is initialized, the structured information will be recorded and stored to a particular segment of the disk. On the other hand, the information will change with the changes of partition information so that it is called partitioning scheme.

Basic MBR Disk Layout

In details, the organization of the partition table in the MBR limits the maximum addressable storage space of a disk to 2 TB (232 × 512 bytes). And it only supports up to 4 primary partitions, or 3 primary partitions and 1 extended partition combination. However, with the progress of the times, larger storage devices need to be applied to the computer field. Therefore, the MBR-based partitioning scheme is in the process of being superseded by the GUID Partition Table (GPT) scheme in new computers because of GPT partition table disk supports a volume up to 2^64 blocks in length e.g. for disks with 512-byte sectors, that would be 9.44 ZB – zettabytes, 1 ZB is 1 billion terabytes, and the ability to have up to 128 primary partitions. A GPT can coexist with an MBR in order to provide some limited form of backward compatibility for older systems.

Basic GPT Disk Layout

Are you confused with the concept and knowledge behind MBR and GPT? Maybe you just want to know how to identify what disks you are using.

How to check if your hard disk is MBR or GPT?

There are 2 methods to find out which partition style your hard drive is using. One is built-in graphical Disk Management tool. The other is the DiskPart command line.

Method 1: Use Disk Management Tool

Step 1: To open Windows Disk Management, press "Windows Key + R" to open the Run dialog, input "diskmgmt.msc" into the box, and click OK.

Open Disk Management

Step 2: Select the disk (here is Disk 0) you want to check. Right-click it and select "Properties".

View Properties

Step 3: Select the "Volumes" tab. In "Partition style" line, you'll know whether your disk is MBR or GPT.

Check Partition Style

Except Disk Management tool, you can also check using the DiskPart utility in a Command Prompt window.

Method 2: Use DiskPart Command Line

Step 1: To launch DiskPart utility, please click Start menu and type "diskpart" in the Search box. Right-click diskpart.exe and select "Run as administrator".

Open DiskPart

Step 2: Type "list disk" command and hit Enter. A table will display all disks connecting to your computer. If a disk is GPT, it will show an asterisk (*) under the "Gpt" column. If a disk is MBR, it will be blank under the "Gpt" column. In this example, The Disk 1 is a GPT disk, while the Disk 0 is a MBR disk.

GPT with Asterisk

Be careful when creating a 5th partition on a MBR disk. If you want to create more partitions, you have to create a structure of no more than 3 primary partitions plus an extended partition and then create more logical partitions resides on the extended partition. Otherwise, the disk will be converted to dynamic disk. It is not recommended to average users as some users may encounter dynamic disk invalid problems and unable to install OS on a dynamic disk.

To sum up, you may see that GUID partition scheme has more advantages, is that mean you can adopt this kind of partitioning scheme to every disk? No, not all Windows systems support this partitioning scheme.

  • Windows XP 32-bit, Windows 2000, Windows NT 4, or Windows 95/98 cannot read, write, and boot from GPT disks, they will see only the Protective MBR.
  • Windows XP x64 Edition can use GPT disks for data only.
  • All versions of Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Vista, Windows 2003 Server, Windows Server 2008 (R2), Windows Server 2012 (R2), and Windows Server 2016 can use GPT disk partition for data. Booting is only supported for 64-bit editions on UEFI-based systems.

When you are facing those conditions, you can mix GPT and MBR disks on systems that support GPT. However, systems that support UEFI require that boot partition must reside on a GPT disk. Other hard disks can be either MBR or GPT. Besides, both MBR and GPT disks can be basic or dynamic disk.

The major differences between MBR and GPT disk are mentioned above. So you can choose GPT or MBR depending on what you have and what you need to do.

Tips: If you have initialized your new hard disk to either MBR or GPT, and stored data or installed system on either of them, however, you want to apply the other disk layout because of 2TB disk space limit or incompatible OS problem, AOMEI Partition Assistant Pro allows you to realize the conversion between MBR and GPT without data loss, which can be downloaded here.