GPT (GUID Partition Table) is a modern disk partitioning scheme that replaces the older MBR (Master Boot Record). It is closely linked to UEFI (Unified Extensible Firmware Interface) because UEFI requires GPT for booting modern operating systems. The combination of GPT and UEFI enables better hardware utilization, enhanced security, and more efficient disk management.

Differences Between GPT and MBR

• Disk Size – MBR supports a maximum disk size of 2 TB, while GPT allows the use of disks in the petabyte range.
• Number of Partitions – MBR allows only 4 primary partitions, whereas GPT supports up to 128 primary partitions without the need for extended or logical partitions.
• Security and Reliability – GPT stores redundant copies of the partition table at both the beginning and end of the disk and includes a CRC32 checksum for error detection.

Advantages of GPT When Used with UEFI

• Support for Secure Boot – GPT enables the use of Secure Boot, which protects against malicious software during system startup.
• Faster Boot Time – UEFI with GPT minimizes operating system startup time through optimized hardware initialization.
• Better Compatibility with Modern OS – Windows 10/11, macOS, and Linux natively support UEFI and GPT for booting.
• Data Recovery and Redundancy – Unlike MBR, which stores the partition table only at the beginning of the disk, GPT saves copies in multiple locations, reducing the risk of data loss due to corruption.

How to Check If a Disk Is Formatted as GPT?
In Windows, you can check the partition type as follows:

1. Press Win + X and select Disk Management.
2. Right-click on the disk and choose Properties.
3. Under the Volumes tab, check whether the disk uses GPT or MBR.

Alternatively, you can use the Command Prompt:

1. Open Command Prompt as an administrator.
2. Type diskpart and press Enter.
3. Enter list disk – a disk using GPT will have an asterisk (*) in the GPT column.

How to Convert a Disk from MBR to GPT?
Windows provides several methods for converting a disk from MBR to GPT:

• During Windows Installation – When performing a clean installation of Windows, you can wipe the disk and reformat it as GPT using the diskpart tool.
• Using MBR2GPT Tool – Windows 10 and later versions include mbr2gpt, which allows conversion without data loss. Run mbr2gpt /convert /allowFullOS in an administrator Command Prompt.
• Manual Backup and Conversion – If MBR2GPT cannot be used, it is recommended to back up data, delete partitions, and create a new GPT disk using Disk Management or diskpart.

When to Choose MBR and When to Use GPT?

• GPT is recommended for newer computers with UEFI to take advantage of larger disks, more partitions, and advanced security features.
• MBR is only useful if working with older hardware or legacy operating systems that do not support UEFI.

Why GPT Combined with UEFI Is the Best Choice

• Supports larger disks beyond the 2 TB limit.
• Provides better security through redundancy and checksum validation.
• UEFI with GPT enables faster booting and features like Secure Boot.
• Ensures better compatibility with modern operating systems and technologies.

If you're upgrading or installing a new system, using GPT with UEFI is the best choice for improved performance, security, and compatibility with modern hardware.