> MBR vs. GPT

MBR vs. GPT Guide: What’s The Difference and Which One Is Better

Note: this post is much related to Windows rather than Mac OS X, Linux, or any other OS.

When adding a brand new HDD or SSD to computer, we are always asked to initialize the disk along with 2 options:

  • MBR (Master Boot Record)
  • GPT (GUID Partition Table)

initialize hard disk to MBR or GPT in Disk Management

Nevertheless, many people have no idea of this issue so that they have to be hesitating when making a choice between MBR and GPT, and they eagerly hope someone could tell them which one is better or which one they should choose.

Are you troubled by such an issue? If yes, this post is what you are looking for, which clearly introduces the exact difference between MBR and GPT as well as shows how to choose the most proper one for your own HDD or SSD.

MBR vs. GPT: What’s Their Difference


MBR stands for Master Boot Record while GPT represents GUID Partition Table, and they are 2 partitioning schemes for HDD, SSD and removable devices.

To know what partitioning scheme your hard disk is employing, just download and install MiniTool Partition Wizard, which is a free partitioning software to help users explore disk/partition properties, initialize disk (to MBR or GPT), enlarge a partition, change partitioning scheme between MBR and GPT, convert file system between FAT32 and NTFS, and so on.



Then, launch the freeware to get the main window:

view partitioning scheme in MiniTool Partition Wizard

From the screenshot you can see I have 2 disks: one MBR and one GPT.

Since MBR and GPT are partitioning schemes, they are doing the same thing: manage how partitions are created and organized on a hard disk, but they differ from each other in many aspects.

Firstly, MBR and GPT Were Introduced in Different Time

MBR was introduced with IBM PC DOS 2.0 in March 1983 and it is used till now. However, GPT was developed in the late 1990s as part of what eventually became UEFI, and it becomes popular just in recent years.

Secondly, MBR and GPT Have Different Structures

MBR consists of 3 parts, including master boot code, a partition table for the disk, and disk signature. A partition table can hold maximum number of 4 entries for primary partitions in Windows.

However, a GUID Partition Table is composed of a Protective MBR which is used in a way that prevents MBR-based disk utilities from misrecognizing and possibly overwriting GPT disks, a primary GUID partition table header which records its own size and location and the size and location of the secondary GPT header, a primary GUID Partition Entry Array, a backup GUID Partition Entry Array, and a backup GUID Partition Table Header. A GUID partition table could contain up to 128 partition entries in Windows.

mbr vs gpt screenshot This chart comes from https://www.schoonepc.nl/instal/partition.html


Thirdly, Supports on Disk Capacity and Partition Amounts Are Different

Support on Partition Amounts
Since an MBR partition table can hold 4 primary partition entries at most, we are only allowed to create the maximum number of 4 primary partitions on an MBR disk. If we want to create more partitions, we have to create an extended partition where lots of logical partitions could reside. However, a logical partition can’t be set active.

On the contrary, a GPT disk theoretically allows an almost unlimited number of partitions, but Windows implementation restricts it to 128 partitions. Each partition on GPT can function like a primary partition on MBR disk.

Support on Disk or Partition Capacity
We can only use 2TB or 16TB of a hard disk’s capacity no matter how large the disk is, if we initialize it to MBR. If the disk is using the traditional 512B sector, we can only use 2TB. If it is using 4Kn (4K native) sector, we can use 16TB.

However, a GPT disk can be up to 2^64 logical blocks in length, and logical blocks could be 512 bytes or 4K in size. Therefore, a GUID partition table disk can grow to a very large size compared with MBR partition table disks. Actually, there is no need to talk about disk or partition capacity limit of GPT since there will be no hard disk exceeding the limit in a very long time.

Fourthly, MBR Differs from GPT in Compatibility

All current Windows operating systems can use GPT partitioned disks for data, such as Windows 7, Windows 8, Windows 10, Windows Server 2008, Windows Server 2012, and Windows Server 2016, but only their 64 bit versions support booting from GPT disk when UEFI boot mode is supported and enabled.

In addition, the 32 bit version of Windows XP can only see the Protective MBR, and even the 64 bit version can use GPT disk for data only.

At Last, They Have Different Boot Mode

If motherboard of our computer supports Legacy boot only, we can only boot Windows from MBR disk. To install Windows on GPT disk under this mode, you’ll receive the error message "Windows cannot be installed to this disk. The selected disk is of the GPT partition style".

Windows cannot be installed to GPT disk in Legacy boot mode

Or Windows won’t start if it is already installed on GPT disk under Legacy boot mode.

However, if motherboard of our computer supports UEFI boot only, we can only start Windows from GPT disk. To install Windows on MBR disk, you’ll receive the error message "Windows cannot be installed to this disk. The selected disk has an MBR partition table. On EFI systems, Windows can only be installed to GPT disk".

Windows cannot be installed to MBR disk on EFI systems

Similarly, Windows will be unbootable if it is already installed on MBR disk in UEFI boot mode.

But luckily, current motherboards support both Legacy boot and UEFI boot, so you only need to enable the CSM (Compatibility Support Module) in BIOS when you want to boot Windows from both MBR disk and GPT disk, or enable UEFI when you want to boot from GPT disk, or enable Legacy BIOS while you plan to boot from MBR disk.

In addition, even if your motherboard supports one boot mode only, you can still find solutions from the article Windows Cannot Be Installed to a Disk? Here Are Solutions.

Tweet Your New Findings


Then, let’s talk about which partitioning scheme is better, MBR or GPT.

MBR vs. GPT: Which One Is Better or Which One to Choose


Please read all contents in this part and then choose the most proper partitioning scheme for your SSD, HDD, or even removable device.

GPT is better if you are planning to create more than 4 partitions.
We have said an MBR disk can hold 4 primary partitions at most while a GPT disk supports up to 128 primary partitions in Windows, so you can choose GPT if you want more partitions.

Trick:
A dynamic disk also supports up to 128 partitions, so you can choose either Dynamic Disk or GPT disk if you demands for more partitions only.

But note on dynamic disk Windows can only be installed to a volume that was converted from a basic partition and retained an entry in the partition table. Simple volumes converted from basic partitions do not have an entry in the partition table unless they were system or boot volumes prior to conversion. This information is required to perform fresh installations of on dynamic volumes.

…………… From Microsoft


GPT is better than MBR if your hard disk is larger than 2TB.
Since you can only use 2TB of space from a 512B sector hard disk if you initialize it to MBR, you’d better format your disk to GPT if it is larger than 2TB. But if the disk is employing 4K native sector, you can use 16TB space.

Tip: even if your MBR disk is saving data, you still have a chance to convert it to GPT without data loss. Detailed steps will be introduced in the last part of this post.


GPT is better if you seek for security.
GPT disks use primary and backup partition tables for redundancy and CRC32 fields for improved partition data structure integrity, so you can choose this partitioning scheme if you value data security.

Choose GPT rather than MBR for your system disk if UEFI boot is supported.
Compared with booting from MBR disk, it’s faster and more stable to boot Windows from GPT disk so that your computer performance could be improved, which is largely due to the design of UEFI. Please remember to enter your computer’s BIOS and enable UEFI boot if it isn’t.

Choose MBR for system disk if your motherboard doesn’t support UEFI boot.
Under Legacy boot mode, you can only initialize your system disk to MBR if you want Windows bootable.

Choose MBR as system disk if you have a 32 bit Windows to install.
Only 64 bit version of Windows can boot from GPT disk.

Choose MBR for system disk if you are still using the very old Windows OS.
If you are running Windows XP or older systems, MBR is the only choice for system disk even if it is a 64 bit system. If not, Windows will be unbootable or cannot be installed.

Tweet Your New Findings


Well, how can we initialize a disk to GPT or MBR, or convert a disk that already saves data between MBR and GPT without losing data? These are what we will talk in the following part.

MBR vs. GPT: How to Initialize or Convert Disk Without Data Loss


How to Initialize Disk to MBR or GPT
It’s very easy to initialize a new hard disk to either MBR or GPT, which could be done in both Windows Disk Management and MiniTool Partition Wizard.



  • In Disk Management:
  • Press on Win and R key to open Run and type diskmgmt.msc to launch Disk Management. Then, you’ll be asked to initialize the newly added hard disk, where you can choose either MBR or GPT.

  • In MiniTool Partition Wizard:
Launch the program to get its main window:

mbr vs gpt initialize disk

MiniTool Partiiton Wizard initializes the newly added disk to MBR by default, but you can select the disk and choose "Initialize to GPT Disk" or "Convert MBR Disk to GPT Disk" feature from the left action panel to convert the disk to GPT if you want GPT.

At last, click "Apply" button to perform the change.

But what if the disk has been saving lots of data?

How to Convert Disk Between MBR and GPT Without Data Loss

  • In Disk Management:
  • In this case, if you also turn to Disk Management, you’ll need to backup important files, and then delete all existing partitions. If not, the option "Convert to GPT Disk" or "Convert to MBR Disk" will be grayed out:

    convert disk to mbr or gpt in disk management

    Trick: if you want GPT disk just for creating more partitions, converting MBR disk to dynamic disk is better than converting to GPT, because the former doesn’t require deleting partitions. But if you want to break the 2TB limit or pursue other features of GPT, convert it to GPT.


  • In MiniTool Partition Wizard:
Alternatively, you can use MiniTool Partition Wizard to do the conversion, which can keep your data and partition intact.



Firstly, launch the program to get its main window:

convert disk to MBR or GPT in Partition Wzard

Then, select the MBR or GPT disk that you want to convert, and choose "Convert MBR Disk to GPT Disk" or "Convert GPT Disk to MBR Disk" from the left action panel.

At last, click "Apply" button to execute the change.

Tweet Your New Findings


Kindly Remainder

MiniTool Partition Wizard 9.1 supports converting a data disk to MBR or GPT, and the coming version namely MiniTool Partition Wizard 10 is capable of converting system disk from MBR to GPT with keeping Windows bootable, but converting system disk to GPT should be on the basis that UEFI boot is supported and enabled in your BIOS. Of course, converting data disk between MBR and GPT is supported in the new version, too. Please follow us on Google+ or Facebook to get the latest product information if you are going to convert system disk to GPT.


Now, most of you would know which partitioning scheme is better, so it’s time to initialize your new HDD/SSD to MBR or GPT, or convert old HDD/SSD between MBR and GPT. Should you have any questions, feel free to leave us messages in Comments part or send us an mail to support@minitool.com.