Should I Use GPT or Not? - An Expert's Guide

The MBR is better for some older versions, but if you are using a Windows operating system higher than the Windows 7 version on a system with SSD, you should opt for GPT. GPT is much better for modern systems and high-capacity storage devices. The MBR partition table schema stores partition information in the first sector of the disk. The entry for each partition is 16 bytes and the total is 64 bytes, so the maximum number of entries that the MBR partition table can store is four. In other words, MBR partitions can have up to 4 partitions.

But many users are not satisfied with 4 partitions and want to create more partitions. To remove this limitation, the extended partition is introduced. Users can create multiple logical partitions on an extended partition. The following image shows the MBR partition scheme. Some hard drive manufacturers are trying to expand the size of the sector to break the restriction that the MBR partition plan is not appropriate for disks larger than 2 TB.

That's why you can find some hard drives whose sector can be 1024 bytes or even 2048 bytes. However, expanding the sector brings problems such as disk speed. Therefore, it is not widely accepted. The arrangement of the logical sectors that constitute storage devices is described by a scheme called LBA (Logical Block Addressing). A label represents by sector, LBA0 represents the first logical sector of the disk and the last LBA represents the last logical sector.

The capacity of the hard drive can be calculated by multiplying the number of logical numbers by the size of each sector. Currently, the standard logical sector size is 512 bytes. Therefore, a 2 TB hard drive will contain 3,906,250,000 512-byte sectors. But the computer system requires 32 bits of information to represent this large number. In other words, if the disk capacity is greater than what can be described with 32 bits, an additional bit, 33 bits, would be needed. The MBR scheme sets a limit of 32 for the number of bits that can represent the number of logical sectors.

The maximum number that can be addressed with 32 bits is 4,294,967,295, that is, 2,199 TB of capacity for a 512-byte sectoral hard drive. This means that the MBR partitioning scheme cannot address a capacity greater than 2.2 TB. In the MBR partitioning scheme, the partition table takes up a total of 64 bytes of space to identify the partition type, location, etc. It takes 16 bytes to record the information on a partition. Therefore, the MBR partition table can contain information from four partitions, which means that you can only create 4 partitions on a hard drive.

If you have created 4 main partitions and there is still unallocated space, the free space will be unusable. To overcome the barrier, you can create an extended partition, a special type of primary partition, and then create multiple logical partitions on the extended partition. All versions of Windows, both 32-bit and 64-bit, including the latest version of Windows 10, are compatible with MBR in terms of data and system compatibility. If you install Windows, such as Windows 10, on an MBR disk and have problems, don't question the MBR. Just check if your motherboard is in BIOS mode. The GPT does not have the limitations of the MBR.

GPT can contain an almost unlimited number of partitions, and you don't need to create an extended partition for them to work. In addition, the disk capacity size is no longer limited to 2 TB. The GPT partitioning scheme allows up to 64 bits of information to be used in logical sectors. Theoretically, the disk capacity that GPT can support can be 9.4 ZB (1ZB %3D 1024 EB, 1EB%3D 1024 PB, 1PB %3D 1024 TB, 1TB %3D 1024 GB).Some users may wonder if it's OK to use Legacy BIOS if the motherboard is UEFI.

The advice is that, considering performance and speed, don't use an old BIOS unless the capacity of your hard drive or SSD is very small. EFI+GPT takes up more disk space (approximately 100 MB) than BIOS+MBR. If 100 MB matters a lot on your hard drive, you can choose Legacy BIOS. GPT disks automatically back up the main GPT header and partition entries in the last sectors of the disk. That's why GPT disks are more secure and reliable than MBR disks.

When the GPT header or partition table is corrupt, these backups will be useful for restoring the data. If you want to configure partitions on a storage device, MBR and GPT will normally continue to be offered as options. However, in principle, GUID partition tables have become the standard solution for modern hardware because they support an unlimited number of partitions and have no restrictions on the size of the storage device or partitions (or at least none that will be relevant in the near future).In addition, for disks with more than 2 terabytes of memory, GPT is the only solution. Therefore, using the old MBR partition style is now only recommended for older hardware and older versions of Windows and other older (or newer) 32-bit operating systems. If a third-party application is used, no data loss occurs during the conversion from GPT to MBR or MBR to GPT. If you have an external hard drive or SSD and your PC supports the GPT partition, you must format the drive with GPT. Other than that, you can convert between MBR and GPT without data loss or partition a hard drive to a GPT or MBR partitioning scheme.

For example, if you prefer a faster boot time it is recommended to use a GPT disk as your system disk; if your computer is BIOS-based choose MBR as your system disk; while if you use a disk of less than 2 TB for data storage both GPT and MBR work well. GPT writes information to several areas of your drive and includes a secondary backup GPT.