Whether you build a computer from parts or buy one off the shelf, understanding how computer hardware works is important. This knowledge will make troubleshooting and comparing systems easier.
The motherboard is the main circuit board that connects and allows communication between all other components. It has memory slots, a power supply unit (PSU) and fans that help to cool the system.
Motherboard
The motherboard provides the central backbone connectivity for all internal and external computer hardware. Whether you are building a high-performance gaming rig, powerful content creation workstation or simple home office PC, choosing the right motherboard is an important first step.
Choose a motherboard with an appropriate CPU socket for the type of CPU you plan to install. Determine if the motherboard supports overclocking to maximize performance. Check for expansion slots for dual in-line memory modules (DIMMs); peripheral component interconnect (PCI) and PCI Express (PCIe) connections; storage devices such as hard disk drives and solid-state drives; and networking cards.
Some motherboards include temperature, voltage and fan-speed sensors for monitoring system components. Other advanced features include a built-in NIC for wired Ethernet, debug LEDs and backup power supplies to mitigate the effects of power outages or failures.
Processor
The processor is the brain of the computer, telling everything from the GPU to disk drives and the screen what to do. It can have anywhere from one core to many.
The control unit fetches instructions from main memory and decodes them using binary decoder circuitry. It then controls the flow of data between CPU and other components by addressing them via internal buses.
A series of high-speed storage called registers inside the CPU holds current and past data for immediate calculations. It also handles basic arithmetic and logical operations like addition, subtraction, multiplication, and division. Until recently, the Northbridge chip on the motherboard and the Southbridge chip on the board connected the CPU to high speed components like RAM and the display. Today, they’re often integrated into a single “chip set”. [51]
Memory
All the data that your computer needs to play a video game or stream a movie is stored in RAM so that the processor can get to it quickly. This shuffling of data between the CPU and RAM happens millions of times every second. When an application or file is closed, the old data is purged from RAM and replaced with new data to support the next task.
Modern CPUs can process huge amounts of data extremely fast, but they need quick and easy access to all that data. To do so, the CPU requires a type of memory called primary or level 1 cache.
Graphics Card
A graphics card (also known as a video card) is what makes your computer’s screen look real. It takes the binary information sent from the CPU and translates it into the pixels you see on the screen. It also creates a wireframe out of straight lines, rasterizes the image, and adds lighting, texture and color.
The GPU is like the artist of your computer — it gives life to all the vibrant colors and crisp details that make games and high-definition movies so realistic. The GPU’s performance depends on its connection to the motherboard and the speed at which it receives instructions from the CPU.
Most modern PCs have a dedicated graphics card that plugs into an expansion slot. However, some small-form-factor computers and laptops use integrated graphics chips instead.
Hard Drive
The hard drive is the data storage device for the computer. Its size is 3.5-inch (used in desktop computers) or 2.5-inch (used in laptops). Modern HDDs use a single data/control cable, as opposed to older interfaces that used separate cables for each function.
A motor spins the disk platters, and a second motor drives a read/write head over them. The heads can be steered with an actuator arm, which allows them to sweep across the entire surface of the disks. The heads never make direct contact with the magnetic platter surfaces, so they are protected against mechanical failure caused by impact or vibration.
A DSP in the drive electronics processes the raw analog voltages from the heads, using PRML and Reed-Solomon error correction to decode data, then sends it out the standard interface. The DSP also performs bad sector remapping and other internal tasks.