Pc components general

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As an aspiring overclocker it is crucial to understand the role that each component of your PC plays. Here is a very general overview of the components found in most of today’s PCs.

What is a PC?

What we today refer to as a PC or a Personal Computer basically consists of the two key elements of hardware and software. Hardware is the “box” itself, or perhaps more precisely, the components inside it. The software is what allows you to “talk” to the hardware, although software has also evolved over the years and has largely become a visual interface that is easy to use. The two work in tandem, so having slow or inadequate hardware means that your software will run slowly.

One piece of software every computer needs is an Operating System, or OS. This is the base platform upon which you run all of your software applications. There are many operating systems to choose from, although today the most popular is Microsoft Windows 10. Many systems however use older Microsoft Windows versions such as Windows 8, 8.1 and Windows 7. Linux is also a type of operating system that is slowly gaining more popularity and is in general free to download and install. One of today’s most popular Linux distributions is Ubuntu.

Once you’ve installed your operating system you’ll also need to install the device drivers. These are relatively small chunks of code which allow the OS to communicate with all other parts of the system. Without drivers your operating system will not work correctly and will also not detect peripherals like mouse, keyboard, printers etc. Many device drivers are built into the operating system. In fact newer OSes like Windows 10 can now automatically detect and install most drivers making driver installation far easier than in the past.

Although software installation can be complicated in some instances, there are many guides available that focus on PC hardware, and how to construct a modern PC from the ground up. If you have never built your own PC, as an aspiring overclocker, it’s a great way to get started.

What Components Make a Up Modern PC?

A modern, consumer PC is made of following components, each of which is described thusly:


Known as the Central Processing Unit, or CPU, this component can be described as the brain of the PC and is responsible for the majority of data computing and logical analysis. The CPU is usually the first item to consider when planning what parts to get when building a PC, as it often dictates the rest of the components you will need. For example, certain types of processors only work with certain motherboards, graphics cards, memory, etc.

In recent years CPUs have featured multiple cores. Current CPUs on the market range from dual-core CPUs which include two physical CPU cores in one chip, to deca-core CPUs which integrate ten CPU cores. More CPU cores generally means more performance. CPU cores work at specific clock speeds, i.e. the speed at which the CPU can complete a work cycle. Generally, higher clock speeds equate to better computational performance.

Most current Intel and AMD processors also integrate graphics and video capabilities, which in the past was the responsibility of either the chipset or graphics card. Vendors such as Intel and AMD manufacture processors that can be bought at a broad range of price points depending on a range of features such as core count, clock speed, cache memory sizes and other features.

Note: AMD use the term APU as well as CPU to refer to processors which integrate Graphics and CPU on one piece of silicon (also refer to ‘die’). APU mean Accelerated Processor Unit, a name that refers to the GPU being able to accelerate specific workloads traditionally taken care of by the CPU.

Some CPUs are advertised as being ‘unlocked’, this means they are designed specifically with overclocking in mind. In the case of Intel, current ‘K’ model processors, for example the Intel Core i7-6700K and i5-6600K, allow users to modify several parameters in order increase the processor’s performance.

System Memory (RAM)

The RAM or Random Access Memory of a PC is where data is primarily stored after being retrieved by the system hard drive. In the human brain analogy, RAM can be compared to short term memory, allowing data to be accessed and read quickly. Most modern Operating Systems, including Microsoft Windows 10, recommend at least 4GB of RAM, although high performance systems may use 16GB, 32GB or more.

Note: 32-bit systems are limited to a maximum capacity of 4GB. For a PC to be able to utilize more than 4GB of RAM, the system must have a 64-bit compatible CPU and operating system.

Two key factors that influence system performance and have a direct relationship with the CPU; bandwidth and clock speed. In this proportional relationship, faster CPU clock speeds and higher memory bandwidth channels equate to greater data transfer rates, which in turn lead to improved performance.

Memory standards are continually evolving to keep up with the demands of modern CPUs. The most common memory standard used today is DDR3 SDRAM (Double Data Rate 3, Synchronous Dynamic Random Access Memory), however the latest CPUs from Intel now use the latest DDR4 standard.

To further increase the memory bandwidth, a dual-channel and quad-channel memory architectures were developed. Dual and quad channel memory architectures allow for improved performance although you will need to install your memory modules in pairs to take advantage of this feature.


The motherboard, or mainboard, is the component that really brings together all the others, and as such, is often considered one of the most important components of a PC, and one that should be chosen carefully. The motherboard connects together the CPU, the RAM, and all attached drives via the chipset, which can perhaps be best described as the central nervous system, or spine of the PC. The chipset is usually a differentiating feature of the motherboard, frequently a central element in the motherboard product name. For example the ASUS Z170-A motherboard is based on the Intel Z170 chipset..

Modern chipsets like the Intel Z170 chipset are more integrated than in previous two-chip solutions which typically used a North and South Bridge configurations. Many advanced features have been removed from the chipset, for example the memory controller, 2D/3D graphics and dedicated video decoding/encoding are now usually found in the CPU itself .

Today the chipset is more commonly responsible for connectivity such as USB, SATA and PCI, PCI Express as well as audio and networking capabilities. To expand a PC’s capabilities and add specific components, motherboard also supports a range of add-in-boards (AIBs) or cards that add additional functions such as dedicated graphics processing via PCI Express slots mounted on the board.

Another important feature of the motherboard is the BIOS, or Basic Input Output System. This is the underlying software layer that connects individual hardware components together. It’s important that advanced users and overclockers learn to configure the BIOS settings in order to manipulate boot priority, drive configurations as well as important CPU and memory configurations. The BIOS is in many ways the heart of overclocking.

When selecting a motherboard, one very important consideration is the motherboard’s form factor or size. Generally, there are four common form factors available each characterized with a different overall size of PC build. In order of size (largest first) these form factors are E-ATX, ATX, Micro-ATX and Mini-ITX.

The form factor of the motherboard will ultimately dictate the eventual size of the PC, and of course the kind of chassis used. Standard ATX motherboards require a full sized tower chassis, but a Micro-ATX build can be housed in a smaller mid-tower chassis. E-ATX motherboards are typically high-end or workstation models and will need a specialized E-ATX compatible chassis. At a mere 17cm x 17cm, Mini-ITX motherboards have become increasingly popular, and are ideal for home theater or compact, portable gaming PC builds.

Graphics Card

The role of the graphics card has evolved in the last ten years or so, with first the chipset, and then more recently, the CPU itself taking a more important role in 2D and 3D graphics processing and video playback, the traditional role of the graphics card. Although the most common type of 2D and 3D graphics processors today reside inside the CPU and are referred to as Integrated Graphics Processors or (IGPs), most 3D gaming titles require a higher performance, discrete Graphics Card. Currently there are two companies that develop discrete Graphics Cards; current market leader Nvidia, and AMD.

Graphics cards from Nvidia and AMD are designed specifically for 3D gaming, adding a powerful GPU or Graphics Processing Unit that allows far faster frame-rates and vastly more life-like graphics rendering at far higher screen resolutions. The GPU can also be used to accelerate other specific tasks such as video encoding and rendering.

Almost all modern graphics cards interface with the other components on the board via a PCI Express slot. Most motherboards will offer at least one or more PCIe x16 lane specifically for connecting a graphics card. Some enthusiast motherboards provide up to four PCI Express slots so that two, three or a maximum of four graphics cards can be installed simultaneously using either SLI (NVIDIA) or CrossFire (AMD) technology, further boosting 3D graphics rendering performance.

Most modern graphics cards offer a choice of VGA, DVI, HDMI or DisplayPort options which can connect up to three or even four displays in a choice of extended or clone desktop configurations. High-performance graphics cards also require substantially more power, with many modern cards requiring a combination two 6-pin and/or 8 eight pin power connectors drawing anywhere up to 250 watts or more. Note: Adding a discrete graphics card will almost certainly impact the overall power draw of the PC and the power supply used.

Hard Disk Drives (HDDs)

Hard disk drives (HDDs) and Solid State Drives (SSDs) are both types of non-volatile memory, retaining stored data even when powered off. Using the analogy described above in reference to system memory (RAM), these kind of drives are essentially the long term memory of the computer. Modern PCs use drives to store all digital data including the operating system and other installed software.

Hard disk drives have for the last few decades been the most commonly used storage medium used in PCs. Hard drives, as they are commonly referred to, are mechanical and contain a physical spinning disk (or platter) housed within a hermetically sealed metal case. The spinning disks are read by magnetic heads which are in turn arranged on a moving actuator arm which reads and writes the data from the disk. Although hard drives offer large capacities of up to 8TB (Terabytes) at affordable prices compared to SSDs, they can suffer damage from physical or electrical shock which often results in data loss.

Most desktop PC hard drives are made using the 3.5 inch form factor. Note: The 3.5 inches refers to the width of the disk within, not the dimensions of the physical drive which is actually 146mm x 101.6mm. Laptops and Notebook PCs use smaller 2.5” hard drives.

In the last ten years or so, hard drive capacities have rapidly grown. Today’s hard drives are described in TBs or Terabytes (n.b. 1TB = 1000GB) whereas for past decade it was more common to refer to drive capacities in Gigabytes (GB). The smallest desktop hard drives on the market as of mid-2016 are 1TB. In terms of hard drive purchasing, many users consider guarantee length to be of vital importance.

In terms of connectivity most hard drives now connect to the motherboard using the SATA (Serial ATA) bus interface. Currently the most common SATA standard is SATA 3.0 which operates at speeds of up to 6gb/s. Although there are different speeds on the market, the majority of hard drives sold today use a 7200rpm spindle accompanied by up to 64MB of cache memory.

PC motherboards usually offer several SATA ports, allowing you to connect and install several hard drives in one PC, so it’s not surprising that additional hard drives represent one of the most common upgrades for DIY PC builders looking to expand the storage capacity of their PC.

Solid State Drives (SSDs)

Although hard drives are still used to store large data files including movies, video games and other large files, most PC’s today use a Solid State Drive or SSD. SSDs store data on solid NAND memory chips as opposed to a mechanical spinning disk and have become increasingly popular due to their vastly superior read and write speeds compared to traditional mechanical hard drives. SSDs offer significantly improved responsiveness, faster system booting and are generally more robust, having no moving parts.

For the majority of users today the SSD is usually where the Operating System and common applications are installed as well as the storage of general user data which today includes videos, photographs, music and other media. SSDs prices have dropped significantly in recent years making them an essential choice for any PC build. Common capacities today range from 120GB to 1TB.

The most common SSD form factor mimics that of the the standard 2.5” hard drive (making an SSD an easy and effective upgrade for older notebook PCs) and measure 100mm x 69.85mm. SSDs also commonly use the SATA 3.0 standard to connect to the motherboard, although newer standards have been introduced that offer high potential bandwidth more suited to the fastest SSDs on the market.

New standards and form factors include mSATA drives which use a card-like design that can connect directly to the motherboard (i.e. no cable is used). mSATA drives have a smaller form factor than a standard SSD making the ideal for portable, space-constrained devices such as laptops and netbooks. The mSATA specification uses standard SATA signals over a PCI Express mini-card connector.

M.2 is the successor to mSATA and delivers a boost in performance by using the PCI Express data lanes of the motherboard directly. M.2 again interfaces directly with the motherboard and uses 4 lanes of PCI Express and has the potential bandwidth of up to 32Gb/s compared to SATA 3.0 which is limited to 6Gb/s.

Optical Drives

Optical drives are drives that allow the PC to read removable disks like CDs, DVDs and Blu-ray disks via an optical laser. Read and write capable DVD ROMs were ubiquitous in modern PCs until a few years ago, allowing users to make their own blank DVD media in capacities of 4.7GB and 8.5GB (for dual layer discs). This remained a useful and affordable way to backup and store data such as images, photos, music and video. Today few people use DVD writers to create their own disks as the arrival of significantly higher capacity hard drives prove to be much more convenient.

Blu-ray readers are of course essential for users who want to playback HD Blu-ray content on their PC, which of course have now displaced DVDs as the most common form of removable media. Blu-ray writers allow users to take advantage of the 25 or 50GB storage capacities of Blu-ray data disks.

Modern optical drives use the SATA interface and connect to the motherboard in the same way as hard drive and SSD media. Most overclockers today will not install an optical drive in their system, unless they intend to use it as a home media system and want to watch Blu Ray disk content for example.

Power Supply (PSU)

The power supply (commonly referred to as a PSU) is arguably the most important component in the PC, and yet it is frequently the most overlooked. Without a stable and reliable power supply, none of the other components will work at expected levels of stability. Modern power supplies follow the latest ATX specification which offers power delivery for the motherboard, CPU, graphics cards and drives.

The most important feature of any power supply should be it reliability and efficiency. Most power supplies today carry a 80 Plus rating, a voluntary certification program intended to promote efficient energy use in computer PSUs (https://en.wikipedia.org/wiki/80_Plus). 80 Plus outlines six rating levels; 80 Plus, 80 Plus Bronze, Silver, Gold, Platinum and Titanium, each of which refers to power efficiency of between 80% and 96%.

It's important when choosing the power supply to consider what the systems overall thermal profile will be, i.e. how many watts should your newly built PC demand? Many modern CPUs and graphics cards will push the overall power profile beyond traditional 500 Watt or 600 Watt boundaries. Many high performance systems that use high performance CPUs paired with multiple graphics cards can demand as much as 1,000 - 1,500 watt of power. This means either pairing several PSUs together, or purchasing a more expensive 1,500 watt PSU designed for extreme overclocking.


The chassis, or case, in very simple terms is the box in which your finished PC will reside. The choice of CPU, motherboard and graphics will influence this decision regarding chassis. High performance components will generally require a larger, better ventilated, and better equipped chassis, while other systems can be optimized to be as compact as possible, e.g. a Home Theater PC.

If the PC will house a full ATX (form factor) motherboard, then it will require a larger, full tower chassis. Micro-ITX motherboards can be accommodated in smaller chassis. Users who aim to employ multi-graphics solutions will also have to take into account size, and most likely opt for larger chassis.

It's also important to understand the role the chassis will play in terms of ventilation and cooling. Most chassis come equipped with internal cooling fans, designed to maintain airflow and prevent key components from overheating. Larger chassis generally tend to offer better ventilation, while aluminum chassis designs are also optimized to maintain stability. For the majority of PC builds, your chassis will also be influenced according to aesthetics and style, but you may also want to consider additional features such as front access to USB ports an audio jacks.

A well ventilated PC with good airflow within will offer better cooling for the components of your PC, and therefore better overclocking headroom.


While most regular PCs use a chassis, many overclockers instead opt to use a benchtable. A benchtable is like an open chassis. It is way to connect your hardware together and build a PC in an open manner where the user has easy and fast access to all the PC’s components.

What is an Operating System (OS)?

A simple hierarchy for PC usage looks like this; the user interacts with application (also called a program or app), the application interacts with the operating system (for example Windows 10) which in turn interacts with system’s hardware. Note: OS and hardware communication also involve the BIOS and device drivers, but we will not discuss these here.

By far the most commonly used operating system or OS today for the majority of PC users is Microsoft Windows. The Windows family of OSes have been used on PCs for several decades, a fact that means the majority of software in the world is written to be compatible with Windows. Other options such as Linux (of which there are dozens of competing versions or distributions) are increasingly popular with niche users, but in terms of overclocking, Linux is largely problematic.

The latest version of Microsoft Windows is Windows 10. It is available in 32-bit and 64-bit versions as well Home, Pro, Enterprise and Education. The majority of overclockers on HWBOT use either Windows 10 (64-bit, Pro or Enterprise) or an older version such as either Windows 7, Windows XP. Although Windows XP is now 16 years old and has not been officially supported since 2008, it remains a popular choice for specific, often legacy, benchmark applications.

Overclockers usually try to gain a competitive edge by optimizing the operating system as much as possible. They are not interested in having the best graphical user experience for example, and will therefore select minimal color schemes and animations within the OS.

In fact, for many experienced overclockers, OS optimization can be a crucial factor. Instead of just installing the OS at stock retail settings, most overclockers use an image or .ISO of a fully stripped down, optimized and minimal OS. Finding the ideal ISO for specific benchmarking session, can be a decision of crucial importance.

What is the BIOS?

The term BIOS means ‘Basic Input Output System’, and is fundamentally the most basic software level of any PC. Most of today’s motherboards use what is known as UEFI (Unified Extensible Firmware Interface) BIOS which is an updated version of traditional BIOS technology that offers advanced features such as support for drives larger than 2TB, faster booting, better power management services and a more graphical user interface.

Motherboards have a BIOS chip (sometimes referred to as a CMOS chip) installed on the board. This is backed up by a small CR2032 battery that allows the BIOS to retain its configuration even when the system is shut down.

The settings within BIOS will allow you to configure almost every aspect of your PC’s hardware. These include settings that control how drives are installed, settings that affect system performance plus many other configuration options.

To enter BIOS you will have to press or hold down the ‘Delete’ key on your keyboard immediately after you turn on the PC (note: some computers such as notebook maybe use F1 or F10). Once inside BIOS, you can navigate the menu system by either the keyboard (using the ‘up’, ‘down’, ‘left’ and ‘right’ arrow keys) or by using a mouse.

Note: Older, non-UEFI motherboards will enter POST (Power On Self Test) each time it is turned on, checking what components and drives are connected to the system as well a brief function check. POST will briefly display the motherboard and BIOS version as well the hard drives and memory installed on the motherboard. If there is a problem detecting these components, your PC will remain, or ‘hang’ on the POST screen, often with a warning message.

BIOS: Basic Functions

It’s important to note that BIOS design, layout and nomenclature can vary depending on which motherboard brand you are using. Regardless, the motherboard BIOS of a PC is responsible for a variety of functions within the PC including providing system information, options about system booting, health, drive configuration and (most crucially for overclocking) CPU and system memory configuration. Let’s look at these in a little more detail:

System Information

The first page of most BIOSes usually shows the user key information about the system. This includes the BIOS version and build date, CPU information including brand, model and current clock speed, as well as how much memory or RAM is installed. Other information such as date and time is also displayed (it’s important that these are configured correctly for security reasons) as well as language options


Booting, or booting up is a process that describes how you computer initializes. When a computer boots a number of things happen including the loading of your system’s operating system which is usually installed on one of your drives. Within your PC’s BIOS you will boot order menu which basically tells the computer which drive contains the OS.

The boot section of the BIOS will have several other options including fast booting, UEFI modes and more. However one crucial function for new users is the ability to configure the order in which you system boots, i.e. which drive to boot from. This is an important first step when installing an OS from portable media such as a USB drive.

System Health

The BIOS also has a section that deals specifically with the health of your PC. Important information is displayed here, including the temperature of key components like the CPU and motherboard as well as the speeds (usually measured in RPM) of system fans installed. The CPU is often the most thermally sensitive component, CPU temperatures beyond 60o degrees Celsius can be problematic for long periods of time for example.

It’s important that CPU coolers and fans are installed correctly and operate at optimal speeds to ensure sufficient cooling for the CPU. System and CPU fans can usually be set to standard, silent (for quiet operation) or performance for high RPM speeds that help keep the CPU as aggressively cooled as possible. Some motherboards may offer advanced fan control operations including custom fan profiles where fan speeds can automatically adjust according temperature.


Within the BIOS you will find an area which allows you to see which drives are connected to to which port on your system. These can be either HDDs, SSDs or USB connected drives. Most drives will connect using the SATA 2.0 or 3.0 protocol mentioned above. Some older drives and operating systems however may require you to configure your drive in IDE mode or AHCI mode for example. In this section you will find information options about SATA modes, LPM support and S.M.A.R.T. status options.

CPU and Memory Configurations

From an overclocking perspective the BIOS contains the keys the castle. The most important areas are those pertain to the configuration of the CPU and memory (RAM) Adjusting these settings, if done properly, can result in significant improvements in system performance.

Regarding the CPU you will find options to modify the speed of the CPU by adjusting parameters including the base clock, multiplier and voltage. Raising the CPU clock speed may result in system instability however. This may be remedied by increasing CPU voltage, however this may in turn cause the CPU to overheat. Overclocking the CPU may well involve using a trial and error procedure to discover the upper limits of your CPU and the cooling apparatus involved.

Memory may also be tuned and tweaked to improve performance. Many enthusiast grade memory kits are configured to use XMP (Extreme Memory Profile). This is where the memory kit and the BIOS employ a preconfigured array of settings at target frequencies. XMP profiles are designed to make it easier for novice users to use advanced, higher performance memory settings, although seasoned overclockers prefer instead to manually tune and configure the broad array of settings available. Memory tuning can be a little overwhelming for for inexperienced overclockers, but a little patience it can be rewarding and give you the edge in certain benchmarks.

Your first overclocking adventure will involve making subtle adjustments to improve performance, without adversely affecting stability.