PC System Bios Information Guide

As technology has become a larger part of our lives, we’ve learned more and more about computers and how they work. Whereas only 15 years ago, the majority of us didn’t have an internet browser, the vast majority of us now know our operating systems from our applications. The most basic (software based) piece of the puzzle however, is still a mystery to most people. The BIOS.

What is a BIOS?

To understand what a BIOS is, the best place to start is to know exactly how your personal computer functions. During everyday use with it, you’re using your operating system (Windows, iOS or Linux in most cases) to interact with your computer and open applications – otherwise known as “Apps” on mobile devices.

These applications could be anything from Google Chrome, to Adobe Audition, your favourite PC game or Microsoft Word. This is where you’ll spend most of your computer time. The BIOS is what enables all of this to happen.

Optimising the BIOS for PC Gaming Systems

The BIOS is important because it acts as the gateway between boot-up and system performance. You can literally spend thousands of pounds on a new PC gaming system but if the BIOS is setup properly then you are throwing money in to the bin. Optimize the BIOS for increase in computer speed, this especially applies to Windows operating systems. Even a cheap PC gaming bundle that sites like PC PowerZone feature need the best bios setup possible.

The BIOS is a special piece of software usually located in a flash memory drive on your computer’s motherboard and is the very first thing that your computer has to access. Have a think about when you first turn your computer on, and what’s the first thing you see?

It’s not the operating system, but a black screen with some white text detailing some of your computer’s hardware specifications and usually a message saying “PRESS F2 TO ENTER BIOS”.

Your processor normally gets most of its commands from your operating system and the inputs you provide. When you turn the computer on however, there is no operating system to guide your processor. Your processor needs to receive its first instruction (usually to start the operating system) from somewhere, so this is the function the BIOS provides!

What does the BIOS do?

The TL;DR version is that the BIOS gives your processor its first, start-up instructions, activates other BIOS chips and pieces of hardware on the computer, enables hardware to communicate, manages a list of settings including date & time, hard drive boot orders, USB inputs and others & finally, the tasks that gives the chip its name, handling the inputs and outputs along with the operating system.

When starting up, the BIOS usually performs the following steps, in the order written:

Check the CMOS RAM for settings – The CMOS is a chip on your motherboard, connected to and run on a battery, so that it can store settings for the computer even when the computer has turned off. This means that you don’t have to reset the computer’s time and choose which hard drive to boot from every time you turn the computer on.

Device Drivers

Loads device drivers and interrupt handlers – You’ve likely seen messages on your Windows PC every time you plug in a new gadget: “Loading device drivers”. Device Drivers are what enable your system to run the new gadget you’ve plugged in, such as a mouse or keyboard, by identifying it and noting its base hardware configurations.

Interrupt handlers are the translators that enable your system to know that a keypress on the keyboard means you want the letter “A” to show up. The interrupt handler will recognise the signal, tell the CPU what it is, and then sends onto the operating system to show to you on the screen.

Start the computer’s registers and manage power – The processors in your computer will have certain places where each signal will be stored, where certain tasks will be done within the processors and very basic hardware functions will take place. The BIOS holds this information and passes it out into the hardware on startup. It will also manage the power settings for your computer.

Initialise the POST, Power-On Self-Test – The BIOS will test that every piece of hardware in your computer is operating properly and receives power to all its components. If any don’t, your BIOS will inform you before your operating system starts up and stop your computer from booting.

This is done because any power problems in your computer could cause a short circuit and destroy the entire system!

Show you the system settings – This is the detailed black screen you first get when you turn your computer on. It normally displays the chipset manufacturer’s name, some detailed information about the hard drive you’re about to use to boot up and other details. What it shows is normally dependant on the BIOS and the manufacturer.

Scan for bootable devices – The next task in the chain is to detect which devices connected to the computer can hold an operating system to boot up. This doesn’t necessarily have to be a hard-drive, it could also be a flash drive, USB stick or CD ROM!

Start the Bootstrap and initialise the operating system – The final piece of the puzzle for starting up your operating system and enabling you to interact with your computer! The BIOS will access your chosen boot drive and start the operating system.

While the BIOS is doing all this work just to start your operating system, if all is well, all you’ll usually see is the black screen with text on it describing the computer’s memory, processor speed, hard disk drives etc., then perhaps a list of boot drives for you to pick one from, and then the loading screen for the operating system!

There are a number of points where there could be errors however and the BIOS will let you know by stopping the sequence and producing a series of beeps or a flashing power light. These are usually in the form of damaged RAM, a power failure with a device, or a short-circuit in a peripheral. This could also happen when you’ve taken out the only bootable device and the BOIS has nothing to boot an operating system from.

Does the BIOS need to be routinely changed?

The good news for you is the BIOS is mostly self-sustaining, hence usually never having to come into contact with it! However, there may be times when you’ll need to change the CMOS settings, such as changing your operating system or installing a new bootable hard drive, setting a password to access the computer or a few other things.

If you ever need to do that, then the very first screen your computer shows on start-up will give you instructions for that!

Your BIOS will very rarely need to be updated, and usually only on older devices as new ones update themselves over the internet and as part of operating system updates.