The difference between UEFI and BIOS, GPT partition and MBR partition.

UEFI is an upgraded version of the motherboard BIOS program, and GPT and MBR are different partition table types. The following is a detailed introduction:

UEFI is different from BIOS:

1.BIOS is the abbreviation of "basic input and output system", which is translated into Chinese as "basic input and output system". UEFI, the full name of Unified Extensible Firmware Interface, is a standard describing a new type of interface in detail, which is a standard firmware interface suitable for computers and aims to replace BIOS.

2. Every ordinary computer will have a BIOS, which is used to load the most basic code of the computer, and is responsible for initializing hardware, testing hardware functions and booting the operating system. UEFI is a concept opposite to BIOS. This interface is used to automatically load the operating system from the pre-boot operating environment to the operating system, thus saving time by simplifying the startup procedure.

3. Due to the limitation of MBR, the traditional BIOS startup can't start the hard disk above 2. 1TB by default. With the continuous decline of hard disk price, hard disks with the size of 2. 1TB will gradually become popular, so UEFI startup is also the mainstream startup mode in the future.

4.UEFI startup needs an independent partition, and the system startup file is isolated from the operating system itself, which can better protect the system startup. Even if the system needs to be reconfigured due to a boot error, only the boot partition needs to be reconfigured. Moreover, for win8 system, using UEFI to start safely and creating a trust source between the certificate stored in the firmware and the platform firmware can ensure that the "known security" code of signature authentication and the startup loader can be executed almost before the operating system is loaded, which can prevent users from executing malicious code in the root path.

The difference between GPT and MBR:

MBR is a traditional partition table scheme, which saves partition information into 64 bytes of the first sector (MBR sector) of the disk, and each partition item occupies 16 bytes, including active status flag, file system identification, start-stop cylinder number, number one, sector number, implied sector number (4 bytes) and total sector number (4 bytes). Since MBR sector has only 64 bytes for partition table, only 4 partitions can be recorded. This is also the reason why the number of hard disk main partitions cannot exceed 4. Later, in order to support more partitions, the concepts of extended partition and logical partition were introduced. But each partition entry is still stored in 16 bytes.

GUID partition table (GPT for short) The disk using GUID partition table is called GPT disk, which is a relatively new disk partition table structure standard derived from EFI standard. Compared with the commonly used Master Boot Record (MBR) partition scheme, GPT provides a more flexible disk partition mechanism. However, not all Windows systems support this partition scheme. GPT has the following advantages:

1, supporting large hard disks above 2TB.

2. There is almost no limit to the number of partitions per disk. Why do you say "almost"? Because Windows system only allows 128 partitions at most. But it's enough.

3. There is almost no limit to the partition size. Another "almost" Because it uses a 64-bit integer to represent the sector number. To exaggerate, the partition size represented by a 64-bit integer is already "astronomical", and you won't see such a large hard disk for several years, let alone partition.

4. The partition table has its own backup. Copies of the same partition table are kept at the beginning and end of the disk. After a copy is destroyed, it can be restored by another copy.

5. Each partition can have a name (different from the volume label).