MBR vs GPT: Which is Better For Your Hard Drive?

Master Boot Record (MBR) and GUID Partition Table (GPT) are two partitioning schemes for hard drives everywhere, with GPT being the newer standard. For each option, the boot structure and the way data gets handled are unique. Speed varies between the two partition options, and requirements are also different. This article explains what they are, what they require, and how they differ.

What is an HDD Partition?

To understand both MBR and GPT, you should understand what a partition is. Partitions are separate sections on a hard drive that the operating system uses to boot and function. Windows displays them as drives in File Explorer, even though they are on the same hard disk drive (HDD). For instance, many laptops have a “system” partition where everything in the Windows Operating System (OS) goes (often the C: drive), plus a hidden “recovery” partition that can get used to restore the system in case of an accident. Another reason to use partitions is to install multiple operating systems on the same HDD (Linux, Windows10, Windows 7, etc.)

What is MBR?

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MBR is the abbreviation for Master Boot Record and manages how partitions are created and organized on the hard disk drive (HDD). MBR uses Bios firmware and stores code in the first sector of the disk with a logical block address (LBA) of 1. The data includes information related to how and where Windows resides so it can manage the boot process in the PC’s primary storage and internal random access memory (RAM), not external memory such as DDR2 and DDR3 memory cards/sticks.

The MBR data stored in LBA 1 of the HDD includes the following:

  • Master partition table: Abbreviated as MPT, the table stores all partition information found on each HDD, including their format type, capacity, and other necessary details. For the OS and the PC to function correctly, they need a record of HDD partitions and sizes and a way to identify the bootable, active partitions. The MPT provides all that essential information.
  • Master boot code: Sometimes abbreviated as MBC, the code executes the launch of the operating system and manages the configuration for the bootup process (to confirm any changes), such as detecting drives, calculating RAM (external), detecting displays, and other essential device and configuration information.
  • Disk signature: Every drive needs a unique identifier, which gets created in the form of a signature. This identifier ensures that the correct drive and partition reads and writes data when using several disks, and it ensures proper PC functionality and security protocol for all read/write data transactions.

The PC’s/motherboard’s basic input/output system (BIOS) looks for the device with an MBR, and then it executes the volume boot code from the partition that has it. Next, the MBR activates the boot sector of the drive to launch the OS.

What is a GPT Partition?

GPT stands for GUID Partition Table. Just like MBR, it also manages the creation and organization of partitions on the HDD. GPT uses UEFI firmware, and it also stores disk information, such as partitions, sizes, and other essential data, just like MBR does in sector one. However, GPT uses sector two because sector one is reserved for MBR and BIOS compatibility. In GPT technical terms, MBR sector #1 (LBA 1) is actually LBA 0 for GPT, and GPT is sector 1 (LBA 1).

MBR Partition SchemeSector #LBA #
MBR1LBA 1
GPT Partition SchemeSector #LBA #
MBR (for compatibility)0LBA 0
GPT1LBA 1

The data stored in the GPT header includes drive information in the form of a GUID partition table. The GUID includes details on drives, partitions, storage sizes, boot information, and other essential data related to boot and functionality.

The GUID Partition Table stored in LBA 1 of the HDD includes information on the following:

  • MBR data
  • GPT data
  • Partition entries data
  • Secondary (a.k.a. backup) GPT data

MBR versus GPT

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The main difference between MBR and GPT is that MBR has some limitations for modern usage. Namely, MBR can only handle four primary partitions and 2TB of HDD space. GPT, meanwhile, doesn’t have these limits at all. There’s no limit to partitions or storage outside of what the drive itself can handle.

However, versions of Windows earlier than 8 can’t boot off of GPT drives. This means earlier OS versions have to use MBR on their primary/boot hard drives.

Another difference is MBR stores all information in one place, which could get corrupted and fail. GPT writes information in several areas of the drive and includes a secondary backup GPT Table for recovery if the first one gets corrupted or fails.

Other than the differences between MBR and GPT mentioned above, GPT is capable of using newer device technologies, and it’s compatible with BIOS/MBR functions for backward compatibility of older, non-UEFI devices. Lastly, bootup is usually faster with GPT and UEFI.

Why Use GPT Partition Scheme?

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If you get an external HDD or SSD and have the choice between MBR or GPT partitioning, you should format the drive with GPT, just so that you can take advantage of the faster speeds, unlimited partitions, and significantly larger storage capacities.

When to Use MBR

There are some reasons to continue using MBR. If you deal primarily with drives below 2TB or older versions of Windows, you might be better off formatting all of your drives to MBR so that you don’t risk breaking compatibility with any of your hardware.

Windows 7 and onward, however, can use GPT. Just not as a boot drive (without a UEFI BIOS). If you’re still running XP/Vista, you might have some bigger problems.

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