UEFI can support remote diagnostics and repair of computers, even with no operating system installed.
Intel developed the original Extensible Firmware Interface (EFI) specification. The Unified EFI Forum is the industry body that manages the UEFI specification.
Many computers with UEFI firmware will allow you to enable a legacy BIOS compatibility mode.
The interface defined by the EFI specification includes data tables that contain platform information, and boot and runtime services that are available to the OS loader and OS.
UEFI firmware provides several technical advantages over a traditional BIOS system which include:
- Ability to boot from large disks (over 2 TB) with a GUID Partition Table (GPT)[13][a]
- CPU-independent architecture[a]
- CPU-independent drivers[a]
- Flexible pre-OS environment, including network capability
- Modular design
- Backward and forward compatibility
UEFI vs Legacy
Rom
Legacy BIOS is run by option Read Only Memory (ROM’s), which collectively is limited to 64 KB of storage. The option ROMs that legacy systems run will only work if they are compatible with the hardware that is running with it. If you upgrade your hardware, you have to update the option ROMs to make sure every aspect of the booting process is compatible.
Language
The next improvement implemented by UEFI has to do with the type of code it uses. UEFI uses C-language. This form of coding is much more simplistic than assembler, which is the type of language that legacy systems require.
boot speed
UEFI’s customization capabilities affects boot time. This is why UEFI boots faster than Legacy systems.