What is the difference between BIOS and UEFI?
East UEFI better or should you use BIOS? Anyone who wants to understand how their personal computer works will find this guide useful. We explain in detail the difference between BIOS (Basic Input-Output System) and UEFI (Unified Extensible Firmware Interface).
UEFI vs BIOS
Here in this article we will take a deep look and explain the difference between BIOS and UEFI. Additionally, we’ll discuss some of their similarities, as well as some of their pros and cons. To begin with, let me first give you a brief description of these two terms.
Are UEFI and BIOS the same?
No, they are different! BIOS and UEFI are two firmware interfaces that allow computers to start the operating system. BIOS uses Master Boot Record (MBR) to record hard drive data information while UEFI uses GUID Partition Table (GPT).
Read: How to check if a disk uses GPT or MBR partition.
What is UEFI?
UEFI was originally developed in 2007 as a standard for modern interfaces. This platform supports a wide variety of modern hardware platforms including ARM (AArch32), x86, x86-64, and Itanium. It means Unified extensible firmware interface. This is the newest and most advanced firmware interface that aims to correct technical shortcomings. Similar to BIOS, it also serves as a bridge, connecting a computer’s operating system to its firmware. UEFI comes with a number of features and benefits that cannot be achieved through legacy BIOS. This technology will eventually replace the BIOS entirely.
In UEFI, the .efi file stores all boot information and is located on the EFI system partition. You will find the bootloader on the same partition. The most important thing to note here is that UEFI bypasses BIOS POST so that the operating system can boot directly. Unlike BIOS, it has no size restrictions, so more components can be initialized simultaneously.
What is BIOS?
BIOS is abbreviated as’Basic input-output system‘. It refers to the computer’s on-board software and is located on the motherboard controller chip. The BIOS connects the hardware components of the computer to the operating system. It loads the boot loader, which starts the operating system and boots the system.
When a system is turned on, the BIOS runs a power-on self-test process that checks for any hardware issues. If there is an error, the system displays an error message or emits cryptic beeps to let you know what is wrong. After the initial check is complete, the bootloader will be loaded from the MBR.
Read: Check if your PC is using UEFI or BIOS.
Difference between UEFI and BIOS
BIOS and UEFI are interfaces used by computers that act as translators between their operating systems and their firmware. These two interfaces are used when the computer begins to initialize its components and start the operating system from the hard drive.
BIOS reads the first sector of the hard drive, which contains the address or code needed to initialize the next device. In addition, the BIOS also determines the boot device that must be initialized for the operating system to run. Because the BIOS has been around since the dawn of time, it continues to operate in 16-bit mode, which limits the amount of code that can be accessed.
On the other hand, UEFI performs similar functions to BIOS but in a slightly different way. It stores all boot and initialization information in an .efi file rather than a firmware file. The file is located on a special partition on the hard drive called the EFI System Partition. On a computer, the EFI system partition consists of the installed operating system boot loader.
The BIOS only works in 16 bits and therefore cannot address more than 1MB of space. Therefore, it can only initialize one device at a time, and it may take longer to start up.
In contrast, UEFI works in 64-bit mode, which means that it has higher addressable memory and thus speeds up the boot process. In addition, UEFI supports networking, which allows you to troubleshoot remotely even without installing an operating system. As a result, most motherboard manufacturers find it a much better choice in most cases. For this reason, it has recently gained popularity.
The next difference between the two programs is that the BIOS stores the boot loader data in the Master Boot Record (MBR). The MBR is located in the first sector of the disk, so it can be easily corrupted, making the operating system unresponsive.
UEFI, on the other hand, uses the GUID partition table, which performs cyclic redundancy checks to identify any corruption issues. Thus, it creates a more robust boot environment which can be easily recovered. With a GPT, it is able to support more than four primary partitions.
Essentially, UEFI brings a lot of new features and improvements that are not possible through BIOS.
Why use UEFI over BIOS?
The BIOS standard was developed in the 1970s and is still used today in PC motherboards. However, it quickly becomes obsolete with newer motherboards that ship with UEFI, which is the most successful motherboard software. Motherboards today come with UEFI, which is significantly more powerful than conventional BIOS. This way the BIOS becomes obsolete and that is why we are using UEFI over BIOS?
Related: How to set and use BIOS or UEFI password on Windows computer.