Short for GUID Partition Table, GPT is a part of the EFI standard that defines the layout of the partition table on a hard drive. GPT is meant as a replacement to hard drives using a MBR partition table, which have a 2.20TB size limitation and extends upon UEFI. Using GPT a drive could support between 8 and 9.4 ZB depending on the sector size.
If you're using a version of Windows that supports GPT while setting up a drive in Disk Management you will receive a prompt similar to the example below. Selecting GPT and clicking Ok will initialize the disk as a GPT partition style.
How do I know if my hard drive is using GPT or MBR?
Use the diskpart command to determine if your drive is using a GPT or MBR.
- Open a Windows command line window.
- Type diskpart and press enter. If prompted for a UAC prompt click ok.
- At the DISKPART> prompt type list disk and press enter. This should give you an output similar to the example below. If GPT is enabled you have a mark under the GPT column for each drive with GPT enabled.
Disk ### Status Size Free Dyn Gpt
-------- ------------- ------- ------- --- ---
Disk 0 Online 119 GB 0 B
Disk 1 Online 119 GB 119 GB
Disk 2 Online 2047 GB 0 B
Disk 3 No Media 0 B 0 B
Disk 4 No Media 0 B 0 B
Disk 5 No Media 0 B 0 B
Disk 6 No Media 0 B 0 B