What is the purpose and function of the BIOS/UEFI?

Licensed Image: BIOS Chip

Keywords:
overclocking, computer, settings, processor, motherboard

Key Takeaway:
The BIOS is a special chip that resides on your computer's motherboard.

Category Insights:
BEGINNER — This article is written to be accessible for newcomers to the topic.

Basic Input Output System (BIOS)

The BIOS is a special chip that resides on your computer's motherboard. It’s programmed with special software called firmware that controls the basic functions of your computer. The BIOS keeps track of what hardware is inside your computer, including things like the processor (CPU), memory, hard drive, USB ports, fans, and even the system clock. The BIOS has default settings that are guaranteed to work. On basic motherboards, there might only be a few settings to change, using a text based interface. You can adjust the settings to customize how your computer works. For example: You can specify in the BIOS what harddrive should be used to boot the system, such as a CD or USB drive. If you make a mistake, you can choose the option to RESTORE DEFAULTS and your BIOS will revert to a working state.

P.O.S.T.

AI generated image: Simulated POST Screen

When you power on your computer, the BIOS/UEFI runs its embedded software first. The user sees will see it as the black screen that appears BEFORE Windows or Linux starts. It may look like the image above or may be covered by the computer manufacturer to simply display a logo. It performs a test called POST (Power-On Self-Test) to make sure everything is working correctly by checking health and compatibility. If something’s wrong, you’ll see an error message. If everything passes, the BIOS checks the boot sector of the hard drive to find the operating system (like Windows or Linux) and will proceed to load it. The BIOS also makes use of a small coin cell battery to keep the system clock running and remember your machine settings. This whole process happens quickly, before your operating system fully takes over.

Unified Extensible Firmware Interface (UEFI)

AI generated image: UEFI Main Screen

The UEFI is an enhanced / fancier version of the BIOS which first saw use around 2010. It provides support for faster boot times, larger drives, and improved security. You will also find new features such as TPM and Secure Boot. UEFI typically offers a more modern user interface with numerous configuration options. There may be hundreds of settings on more advanced systems. Today, the terms BIOS and UEFI are sometimes used interchangeably.

BIOS Updates

Most people do not need to update the BIOS unless there is a specific reason to do so. A BIOS update may be needed to fix a problem, add a new feature, or make the motherboard work with a newer processor. Be careful, because updating the BIOS the wrong way, or losing power during the update, can stop the computer from starting properly. Problems are rare, but are known to happen. If you need to update it, download the correct BIOS file from the motherboard manufacturer’s website and follow the instructions for your exact motherboard model. Your settings should simply carry over from the prior version to the new version.

BIOS Flashback

AI generated image: BIOS Flashback button

Some motherboards have a helpful recovery feature often called BIOS Flashback, although the exact name may be different depending on the brand of motherboard. If a BIOS update does not work correctly or becomes damaged, BIOS Flashback can restore it to the original factory version. To use this feature, check the motherboard manual or the manufacturer’s website because the steps can be different for each model. On many motherboards, BIOS Flashback can even work without a processor installed. Some motherboards also include two BIOS versions stored on the board: a main BIOS and a backup BIOS. This lets the user switch to the backup BIOS if the main one has a problem. Consult the manual for your motherboard.

Fan Curves

AI generated image: UEFI Fan curve screen

High-quality motherboards provide users with the ability to configure individual fans within the system, including CPU, case, and radiator fans. These fans can be managed through either voltage control or PWM (Pulse Width Modulation). Gamers & graphic designers may prefer a more aggressive cooling profile for improved performance, whereas office users might prioritize quieter fan operation. Fan speeds are typically regulated by the temperature sensors integrated into the motherboard and processor.

Processor Overclocking

AI generated image: UEFI CPU overclock screen

Overclocking means adjusting the BIOS settings to make your CPU run faster than usual. This is something gamers often do to boost performance and get a small advantage over others. This assumes the processor and BIOS support the overclocking feature. All modern AMD processors support overclocking while only some of the Intel processors do. AMD does offer Ryzen Master software as a free download. This software has an option to do Automatic Overclocking. It will provide a performance gain but is not intended for maximum performance. Full manual, processor overclocking is beyond the scope of this article.

Memory Overclocking

AI generated image: UEFI RAM overclock screen

Your BIOS may have the option for memory overclocking. This is typically found on gaming computers. Here, you can enable DOCP or XMP which will allow the memory to perform faster. This is a simple way of overclocking your memory. These are predefined profiles that will automatically adjust the memory settings for increased performance. This assumes the memory in the computer supports the overclocking feature. If you want to take it even further, you can manually adjust the memory timings. Manual memory overclocking by adjusting the individual timings is not for beginners and is beyond the scope of this article.