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What Is UEFI? (Unified Extensible Firmware Interface)

The Unified Extensible Firmware Interface loads before your OS

By Mark Kyrnin Mark Kyrnin Writer University of California, Berkeley Mark Kyrnin is a former Lifewire writer and computer networking and internet expert who also specializes in computer hardware. lifewire's editorial guidelines Updated on July 24, 2020 Tweet Share Email Tweet Share Email Accessories & Hardware The Quick Guide to Webcams Keyboards & Mice Monitors Cards HDD & SSD Printers & Scanners Raspberry Pi Older PCs initiate hardware through the Basic Input Output System (BIOS). However, most computers now use an initialization system called the Unified Extensible Firmware Interface (UEFI). There are several advantages and disadvantages to UEFI in modern PCs. ASUSTeK

What Is UEFI

When you first turn on a computer, it doesn't immediately load the operating system. Once the Power On Self Test (POST) is completed on older PCs, the BIOS initiates the operating system's bootloader. This procedure allows the computer's hardware components to communicate properly with one another. The UEFI is a newer specification that defines how the hardware and software communicate within a computer system. The specification involves two aspects of this process: Boot services: Boot services define how the hardware initiates the software or operating system for loading. Runtime services: Runtime services skip the boot processor and load applications directly from the UEFI. This approach makes it act somewhat like a stripped-down operating system by launching a browser. UEFI hasn't completely replaced BIOS. The early specifications lacked POST or configuration options. Newer systems require the BIOS for these purposes but don't offer the level of customization possible in BIOS-only systems.

Advantages of UEFI

The most significant benefit of UEFI is the lack of specific hardware dependence. BIOS is specific to the x86 architecture. UEFI allows PCs to use a processor from a different vendor even if it doesn't have the legacy x86 coding. The other major benefit of using UEFI is that it supports several operating systems without the need for a bootloader such as LILO or GRUB. Instead, the UEFI can automatically select the appropriate partition with the operating system and load from it, resulting in faster boot times. The UEFI also offers more user-friendly interfaces than the old text menus of the BIOS, making it easier to adjust the system. The interface also allows you to run limited-use web browsers and mail clients without launching a full OS.

Disadvantages of UEFI

The biggest problem with UEFI is hardware and software support. For it to work properly, the hardware and operating system must support the appropriate specification. This isn't as much of a challenge with the current versions of Windows and macOS. However, older operating systems such as Windows XP do not support it.

History of UEFI

UEFI is an extension of the original Extensible Firmware Interface developed by Intel. Intel debuted this hardware and software interface system when the company launched its Itanium server-processor lineup. Because of its advanced architecture and the limitations of the existing BIOS systems, engineers developed a new method for handing off the hardware to the operating system that allowed for greater flexibility. Because the Itanium wasn't a huge success, the EFI standards also languished for many years. In 2005, the Unified EFI Forum expanded the original specifications developed by Intel to produce a new standard for updating the hardware and software interface. This consortium includes companies such as AMD, Apple, Dell, HP, IBM, Intel, Lenovo, and Microsoft. Two of the largest BIOS makers, American Megatrends and Pheonix Technologies, are also members. Was this page helpful? Thanks for letting us know! Get the Latest Tech News Delivered Every Day Subscribe Tell us why! Other Not enough details Hard to understand Submit More from Lifewire BIOS Keys by Motherboard (Gigabyte, MSI, ASUS, Etc.) Can I Run Windows 11 on My Computer? How to Install Mac OS on PC How to Enter BIOS on Windows 10 CMOS: What It Is and What It's For How to Disable Secure Boot What Is an EFI File? What Is BIOS (Basic Input Output System)? How to Fix the WHEA Uncorrectable Error What Is a Platform? How to Disable the Function Key on a Dell Laptop Error Code 0xc00000e9: What It Means and How to Fix It How to Fix Error Code 29 Samsung HUTIL v2.10 Review: Free Hard Drive Test Tool How to Enable Secure Boot to Install Windows 11 Latest Windows 10 Drivers (October 21, 2022) Newsletter Sign Up Newsletter Sign Up Newsletter Sign Up Newsletter Sign Up Newsletter Sign Up By clicking “Accept All Cookies”, you agree to the storing of cookies on your device to enhance site navigation, analyze site usage, and assist in our marketing efforts. Cookies Settings Accept All Cookies