A computer’s internal hardware is made up of durable and reliable parts that perform crucial functions. Understanding these components can help you diagnose problems, or upgrade your device to achieve the highest performance possible.
Even though computers are smaller than ever, the basic components are still the same. For example, the motherboard serves as the hub that everything connects to; the processor follows instructions; and RAM stores data for quick access.
Motherboard
The motherboard is a central hub connecting your PC’s functional components so that they can interact. It includes the CPU, a processor that acts as a brain and tells other parts of your computer what to do; random access memory (RAM), a temporary warehouse for data; connectors for the power supply unit and case electronics; and expansion slots that let you add peripheral cards.
Other features on the motherboard include 3.5mm analog audio ports that work with headphones and other stereo equipment; USB ports for storage and connectivity; and a CMOS battery that stores the BIOS settings. Motherboards come in a variety of form factors. Extended ATX boards are the largest (12 by 13 or 12 by 10.1 inches) and can support up to eight RAM slots; ATX motherboards are smaller but still provide four slots; and microATX and mini-ITX boards are ideal for lightweight PCs that only need a few expansion ports.
Processor
The processor is the brain of your computer and tells other hardware components like the GPU, disk drives and screens what to do. There are many different processors from Intel and AMD, with some built to handle everyday computing while others are designed for video editing or pro gaming.
The CPU has four primary functions: fetch, decode, execute and write back. It starts by fetching instructions from memory, which is done using a binary decoder that converts them into signals that other parts of the CPU understand. Next, the arithmetic logic unit (ALU) performs basic arithmetic and logical operations. Finally, the registers hold data and instructions used by other parts of the CPU.
RAM
RAM is the place where short-term data is stored in a computer or laptop. Data stored in RAM is much faster to read than data on a hard drive or SSD, but it’s also limited in capacity.
Most pcs let you install RAM modules up to a certain capacity. Having more memory reduces the number of times the CPU must read from disk, a process that takes longer than reading from RAM.
Single data rate synchronous dynamic RAM (SDRAM) performs data transfers in sync with the processor clock cycle, boosting performance by about 25%. Double data rate synchronous dynamic RAM (DDR SDRAM) increased performance even further by doubling the number of data transfer operations in a clock cycle. It’s available in a wide range of speeds measured in megahertz (MHz). Enhanced data-rate synchronized SDRAM or ECC RAM adds error correction to the mix, improving reliability.
Graphics Card
A graphics card (also known as a video card or graphics processing unit, GPU) transforms data from the CPU into images. These images are displayed on a monitor through an HDMI, DisplayPort or DVI cable.
The GPU needs somewhere to store information and completed pictures, so it uses video RAM, or VRAM. This is high-speed memory that’s dual ported, so the chip can read and write to it at the same time.
Most gaming cards have 4 gigabytes (GB) of VRAM or more. Recent GPUs also decode high-definition video on the card, offloading this task from the central processor. Nvidia is best known for its GeForce line of cards, but AMD’s Radeon series offers competitive options. Intel’s Arc line is newer but aims to compete with Nvidia in the mid-range market.
Hard Drive
The hard drive is where files, programs, and operating systems are stored. It contains several disks inside a solid encasement that spin extremely fast, which gives them the ability to store enormous amounts of data. Hard drives can fail through physical damage (like dropping a drive on its head), or through logical failure such as corrupted files or malware that interferes with hard disk functionality.
A modern hard drive presents a consistent interface to the rest of the computer, independent of the internal data encoding scheme and number of platters and heads within the drive. The hard drive uses an actuator arm with magnetic heads to read and write information on disc-like objects called “platters.” Each platter is divided into thousands of sectors that each contain a unique electric charge. A digital signal processor decodes the analog signals from the heads into binary 1s and 0s, then sends the data out through the standard interface.