MBR Vs GPT: What Are Master Boot Record & GUID Partition Table

Complete guide to two types of disk partitioning Master Boot Record & GUID Partition Table. Also learn the key difference between MBR vs GPT:

If you have recently bought a new PC or installed a new operating system, you must have gone through the process of partitioning the storage drive of your computer. The storage drive isn’t capable of storing data until partitions are created and formatted to either an NTFS or FAT file system.

At this stage, most of us face the dilemma of choosing one or the other partition styles. In this article, we will talk about two styles of disk partitioning- MBR and GPT. Further, we will also discuss the difference between MBR and GPT.

Understanding MBR And GPT

Let’s get started by gaining a basic understanding of MBR and GPT. Let’s begin with MBR.

What Is MBR

MBR stands for Master Boot Record. To explain it more, it is simply a part of a hard disk where all the information about the disk can be found. We can find it in the boot sector and it contains details of types of partitions and also the code which is required at the time booting the operating system of the computer.

MBR can have a lot of different forms, but what is common for all these forms is that they all have a size of 512 bytes, a partition table, and bootstrap code.

Let us look at some features of MBR.

Features Of MBR

These are as follows:

1. The maximum number of primary partitions possible on an MBR disk is 4, where each partition requires 16 bytes space, which makes it a total of 64 bytes space for all the partitions.
2. MBR partitions can be of three types- Primary partitions, Extended partitions, and Logical partitions. As mentioned above, it can have only 4 primary partitions. This limitation is overcome by extended and logical partitions.
3. The partition table in MBR contains details regarding only the primary and extended partition. Also, it is important to understand that data cannot be saved directly on the extended partition and therefore there is a need to create logical partitions.
4. Some of the latest types of Master Boot Record may also have additions like disk signatures, timestamp, and details regarding disk formatting.
5. Unlike the older versions of MBR which could support four partitions, the latest versions are capable of supporting up to sixteen partitions. As the size of all MBR is not more than 512 bytes, disks that are formatted with MBR have a cap of 2TB disk space which is available for use. (Some hard disks are also available with 1024 bytes or 2048 bytes sector, but this can create issues with the speed of the disk and therefore is not a wise choice)
6. It is compatible with all the versions of Windows (32 bit and 64 bit) and the latest version of Windows 10 as well.

Structure Of MBR

Let us look at how a simple structure of MBR looks like. This is explained in the picture below:

Limitations Of MBR

It also has some shortcomings. These are mentioned below:

1. MBR style of partition can only work with disk space not more than 2TB.
2. It can have only up to 4 primary partitions. In case there is unallocated space after creating primary partitions, we can make it usable by creating extended partitions where various logical partitions can be created.

With these limitations of MBR, users often opt for different styles for partitioning. One of the most common styles of partitioning other than MBR is GPT.

Let us first understand what GPT is before we compare it with MBR.

What Is GPT

GPT stands for GUID Partition Table. It is the latest style of disk partitioning and is known to be a quick successor of MBR. GPT maintains the data regarding the organization of partitions and the boot code of the operating system all across the drive.

This ensures that in the event of anyone partition getting corrupted or deleted, data can still be retrieved and there will be no issues with the process of booting. This is one reason why GPT has an edge over MBR.

GPT Disk Layout

The below image shows a simple GPT image layout.

In the above image, we can see that the GPT disk is divided into three parts:

• Primary Partition Table: This is where the protective MBR, GPT header partition, and partition table are located.
• Normal Data Partition: This is the location used for storing personal data.
• Back up Partition Table: This location is utilized to store the backup data for the GPT header and partition table. This is useful in the event of any damage to the Primary partition table.

Features Of GPT

These are as follows:

1. GPT disk provides much more storage space as compared to MBR. Users can create multiple partitions. GPT disk system can create as many as 128 partitions.
2. GPT disk system is a breakthrough when we talk about the limitation of MBR where only 4 primary partitions can be created.
3. GPT disk style makes recovery of data an effortless task.
4. GPT can run checks to ensure the data is secured. It uses CRC values to check the security of data. In case the data is damaged, it can detect the damage and also try to retrieve the damaged data from other locations on the disk. This makes GPT a more reliable choice compared to MBR.
5. The usage of GPT is not limited to just Windows OS but is also widely used by other OS like Mac from Apple.
6. One very interesting feature included in GPT is called “Protective MBR”. This MBR considers only one partition on the entire drive. In such cases, when users try to manage GPT with the help of an old tool, this tool will read one partition spread across the drive. Here is when Protective MBR makes sure that the old tools do not consider the GPT drive to be not partitioned and prevents any damage to GPT data with the new MBR. Protective MBR safeguards the GPT data so it is not deleted.

Limitations Of GPT

• While GPT is compatible with almost all the 64-bit versions of Windows like Vista, Windows 8, and Windows 10, but in case GPT has to be used as a boot drive, the system needs to be based on UEFI. GPT drive cannot work as the primary drive in the case of a system that is BIOS-based.

When is MBR the right choice to make?

The only reason any user will choose MBR over GPT is when Windows is installed on a BIOS-based system and the drive is to be used as a boot drive. MBR formatting will also be a sane choice to make for users who work on drives less than 2 TB or any previous versions of Windows, as it will maintain compatibility with the system.

With the advantages and disadvantages of the two most popular styles for disk partitioning, the advantages and limitations mentioned above will certainly help make a suitable choice.

MBR Vs GPT

To make things easier for our readers below is a comprehensive comparison table between MBR and GPT. The table highlights the major difference between MBR and GPT.

The above table lays down MBR vs GPT performance. Based on the points mentioned above, GPT is far more superior in terms of performance if UEFI boots are supported. It also provides advantages of stability and speed and enhances the performance of the hardware which is largely due to the structure of UEFI.

Let us also look at some other details about MBR and GPT.

The next section of this article talks about finding the most suitable between MBR and GPT for SSD.

MBR vs GPT SSD

Users have to make a choice between MBR and GPT styles of partitioning when a drive is plugged into Windows.

• SSD or Solid-State Drive has a higher price factor attached as compared to Hard Disk Drives. SSD’s have become increasingly popular for data storage. The choice of MBR or GPT partition style largely depends on the capacity of SSD.
• MBR has serious limitations in terms of several sectors and capacity. Logical sectors represent only 32 bits and storage space that can be used for MBR is only up to 2 TB. If space is more than 2 TB, it is labeled as unallocated space and it cannot be used.
• GPT on the other hand allows 64 bits and storage space is 9.4ZB. This also equates to the fact that GPT can use up all the space up to any capacity.
• One more factor that is important to consider is that there is a lot of difference in the working of SSD and HDD. SSD is able to boot Windows far more quickly as compared to HDD. In order to maximize this benefit of speed, UEFI based systems are needed, which makes GPT a better choice.

A choice between GPT vs MBR also largely depends on the Operating System. SSDs are more compatible with the latest versions of Windows- Windows 10. If SSDs are used on Windows XP, it can bring down the lifespan and performance of the drive. This happens because the TRIM feature is not available.

So, in order to make a choice between GPT vs MBR for SSD, the above-mentioned factors have to be considered promptly. GPT clearly makes a more sensible choice for SSDs.

How To Find If Your Computer Has MBR or GPT

Follow the steps mentioned below:

Step 1: Type Disk Management to open the Disk Management tool.

Step 2: Right-click on the disk number.

Step 3: Select “Properties”.

Step 4: Select the “Volumes” tab as shown in the below screenshot.

Frequently Asked Questions

Let us now look at some frequently asked questions which users have when choosing between Master Boot Record vs GUID Partition Table.

Q #1) Which is better MBR or GPT?

Answer: A choice of MBR or GPT depends on the number of partitions one wants to create. MBR has a limitation of only up to 4 primary partitions, whereas GPT allows the creation of up to 128 primary partitions. So, GPT is the most suitable choice if more partitions are to be created.

Q #2) Can MBR and GPT be mixed?

Answer: It is possible to mix MBR and GPT only on those systems which support GPT. GPT requires a UEFI interface. When UEFI is supported on a system, it is important that the boot partition must be on the GPT disk. However, the other hard disks can either be MBR or GPT. One dynamic disk group can accommodate both MBR and GPT.

Q #3) Is Windows 10 GPT or MBR?

Answer: All the versions of Windows can read GPT drives, but booting is not possible in the absence of UEFI. The latest OS like Windows 10, MAC uses GPT. Linux also has in-built support available for GPT.

Q #4) Can UEFI boot MBR?

Answer: UEFI can support both MBR and GPT. It works well with GPT to get rid of the size and number of partition limitation of MBR.

Q #5) What is UEFI mode?

Answer: UEFI stands for Unified Extensible Firmware Interface. It is a software interface that is capable of repairing computer systems in the absence of an Operating system.

Q #6) Are there chances of data loss if GPT is converted to MBR?

Answer: In case of conversion from GPT to MBR or MBR to GPT through Disk Management, it is required to delete all partitions prior to the conversion. In case a third party application is used, no loss of data takes place during the conversion of GPT to MBR or MBR to GPT.

Conclusion

In this article, we have discussed two important styles of disk partitioning–MBR (Master Boot Record) and GPT (GUID Partition Table).

This article aims to highlight the advantages and limitations of MBR and GPT for our readers. We have also made a comparison of GPT vs MBR so that it is easy for our readers to understand the features and limitations of MBR and GPT while making a sensible choice.