CMOS (Complementary Metal-Oxide semiconductor) and BIOS ( Basic Input Output System) are the two most important components of your computer that are situated in the motherboard. For the similar kind of functionality of both the components, most people get confused whether they are similar components with different names or entirely two separate components.
Basically, CMOS and BIOS are two separate components with different functionality but depend on each other in terms of performing their respective job.
In this article, you will find out a detailed discussion about both the components and where you can lay the differences.
Simply put, BIOS is the pre-installed firmware that is responsible for booting up your computer and giving control to the operating system. It is the most fundamental program that runs when you turn on the power button of your computer.
BIOS is responsible for starting the booting process and loading the operating system on your computer. It is considered the most fundamental program of your computer because all the hardware settings such as date, time, RAM frequency, CPU frequency, system configuration details are stored in BIOS. Therefore, by any chance, if your BIOS is corrupted, the computer hardware will not respond to operate and won’t initiate booting.
Functions Of BIOS
POST: BIOS contains all the configuration and instructions for loading your PC hardware. So when you turn on your PC, BIOS runs a test to detect if all the hardware connected to a computer and operating system required for boost up is in order. This test is called the Power On Self Test. If any error is detected through POST, BIOS will display a message to its resolve or produce a beep sound that refers to the problem.
Booting: BIOS does not operate the computer. It just enables all the hardware and operating systems to perform their job. After POST, the process through which BIOS detects the operating system and gives control of the computer is called booting.
BIOS Driver: BIOS drivers are a compilation of programs that are stored in the motherboard’s non-volatile erasable memory. These drivers allow BIOS to use the hardware of the computer and interact with them.
BIOS Setup: BIOS setup is a hardware configuration program that allows the BIOS to configure hardware settings such as computer passwords, date and times, e.t.c.
BIOS is a software or ROM ( read-only memory) that can not store variable data. As it’s software, there must be a memory chip or hardware where this BIOS will be stored in the motherboard.
And that’s where CMOS comes from.
In simple words, CMOS is the hardware or chip where BIOS is stored. CMOS refers to the process of manufacturing the chip that stores BIOS settings. And from that, the chip got its name. When you change the BIOS setting, the information is stored in the CMOS chip. It is memory hardware that can contain only 256 bytes of data.
CMOS is a kind of chip that requires constant electricity to keep the data stored as it is even when the computer is turned off. That’s why an external power source is required to provide a constant current to the chip. And this additional power source is called a CMOS battery.
The CMOS battery is a small coin size lithium-ion battery that lasts more than ten years before it needs to be replaced. When the battery gets dead, the BIOS setting will go back to the default mood. But these days few modern motherboard manufacturers are providing additional power sources even after the battery dies.
Difference Between BIOS And UEFI
UEFI (Unified Extensible Firmware Interface) and BIOS are dedicated to doing the same thing for your computer. But the difference is created by some additional factors of UEFI. For example, UEFI does not require an external memory chip to store the startup data in efi.file on an EFI system partition located in the hard disk. The boot loader is also stored on the EFI partition ensuring a quicker startup time than BIOS. The Security Boot feature of UEFI protects your PC from booting from any uncertified application or software.
BIOS on the other hand is a hassle-free solution for beginners who don’t want to get in trouble using any type of unknown firmware. Also, BIOS provides smooth operation for texted based UI, keyboard, and mouse navigation. Furthermore, BIOS can run multiple operating systems without giving you the trouble of changing settings for each. Moreover, BIOS is a simpler solution for PC users.
Frequently Asked Questions (FAQs)
How To Access BIOS On My Windows Computer?
To set up or enter BIOS in your computer or modify the settings, first you need to access BIOS by pressing the key dedicated for BIOS. This key can be F10, F2, F1, F12 or DEL depending on different manufacturers.
Can I Upgrade My BIOS-Chip?
You can not upgrade the existing BIOS chip by adding an extra BIOS chip with it. You will only be able to upgrade the existing one by replacing it with a new one.
But you can update BIOS information if your BIOS is a Flash BIOS which will allow you to update the BIOS with an external disk and without opening the case.
In Conclusion, BIOS is a program that is responsible for booting up the computer and locating the operating system. And CMOS is the memory chip that carries BIOS settings or information even when the computer is turned off.
Therefore, whenever the contradiction comes to your mind about CMOS and bios, remember one thing that both are the two separate components placed in a computer’s motherboard. Both the components are mutually dependent on each other, but not the same.