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 disk drives (HDD) and solid-state drives (SSD) everywhere, with GPT being the newer standard. For each option (MBR and GPT), the boot structure and how 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?
Before going into details about both MBR and GPT, you should understand what a partition is. Partitions are separate sections on the SSD or HDD that the operating system uses to boot and function. Windows displays them as drives in File Explorer, even though they are on the same disk.
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.) You can also create a separate partition for storing files like images, music, videos, etc., so they remain intact and safe if the OS crashes.
What is MBR?
The Master Boot Record manages how partitions are created and organized on the SSD or HDD. MBR uses Bios firmware and stores code in the disk’s first sector with a logical block address (LBA) of 1. The data includes information on how and where Windows resides to manage the boot process in the PC’s primary storage and internal random access memory (RAM).
What Does MBR Contain?
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 SSD/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 plus 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 using several disks. It also provides 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, which is often the “C:” drive. Next, the MBR activates the drive’s boot sector 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 SSD/HDD. GPT uses UEFI firmware versus the BIOS used in MBR, 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 gets reserved for MBR and BIOS compatibility. In GPT technical terms, MBR sector #1 (LBA 1) becomes LBA 0 when using GPT, and GPT becomes sector 1 (LBA 1). Therefore, on GPT, boot information gets stored on LBA 1 while it reserves LBA 0 for MBR compatibility.
|MBR Partition Scheme||Sector #||LBA #|
|GPT Partition Scheme||Sector #||LBA #|
|MBR (for compatibility)||0||LBA 0|
The data stored in the GPT header includes drive information in the form of a GUID partition table. The GUID consists of 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 SSD/HDD includes information on the following:
- MBR data
- GPT data
- Partition entries data
- Secondary (a.k.a. backup) GPT data
MBR Versus GPT
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 drive space. GPT has no partition limit, so you can have ten partitions if you want and up to 9400000000 TB of SSD/HDD space.
However, Windows versions earlier than Vista can’t boot off GPT drives. Windows 7 and Vista can boot in GPT but with exceptions, such as only on 64-bit systems and by following a specific process. Windows 8 and above work with GPT by default as long as you use a 64-bit system.
Another difference is MBR stores all information in one place, which could get corrupted and fail. GPT writes information in several drive areas and includes a secondary backup GPT Table for recovery if the first one gets corrupted.
Other than the differences between MBR and GPT mentioned above, GPT can use 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.
Quick Recap of MBR Versus GPT
|MBR Partition Scheme||GPT Partition Scheme|
|Maximum of 4 partitions||Unlimited partitions|
|2TB max SSD/HDD disk space||9400000000 TB max SSD/HDD disk space|
|32-bit and 64-bit systems||64-bit systems only|
|Works with any Windows version, no support for macOS||Windows 7/Vista with 64-bit Windows only, Win 8/10/11 by default, macOS by default|
|Stores boot details in one place||Stores boot details in several places, and it creates a backup|
|Slower boot process||Faster boot process|
|Works with older devices||Works with older devices plus new ones, backward compatible with MBR partitions/devices/operating systems|
Why Use GPT Partition Scheme?
If you get an external HDD or SSD, and your PC supports GPT partitioning, you should format the drive with GPT. You can use GPT on HDDs too. It doesn’t have to be an SSD. Operating systems like macOS use GPT by default due to their 64-bit architecture, while Windows 8/10 use GPT if the motherboard supports UEFI. This option lets you take advantage of 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 SSDs/HDDs to MBR so that you don’t risk breaking compatibility with any of your hardware.
Windows 7 and onward, however, can use GPT. Unfortunately, compatibility depends on whether the motherboard and CPU support the UEFI BIOS or it can only work on non-boot partitions. If you’re still running XP/Vista, you won’t get GPT to work at all, leaving you with only the MBR option.
Now that you know the difference between MBR and GPT, you can correctly choose the partition table scheme that works best for your HDD or SSD size, the desired number of partitions, and the OS. While all the technical differences can seem overwhelming to understand and apply, remember that MBR works with drives 2TB or smaller and non-UEFI systems. In comparison, GPT supports drives bigger than 2TB, newer operating systems, and a more significant number of partitions.