Computer hardware is any physical component that contributes to a computer system. This includes the central processing unit, random access memory, motherboard, and computer data storage devices.
CPUs primarily process digital instructions from software applications. They can have multiple cores, enabling them to work on multiple tasks simultaneously. RAM stores temporary information and is volatile, meaning that stored data disappears when power is removed.
Motherboard
A motherboard acts as the skeleton of a computer, connecting essential components to ensure proper operation. It contains circuits, chips, sockets, slots and ports that determine the performance, expandability and compatibility of your computer.
These pathways, called traces, allow data to travel between the different components on the motherboard, including the central processing unit (CPU) and random-access memory (RAM). Motherboards also contain slots for expansion cards like graphics cards.
These cards connect to the CPU through a technology known as PCIe, which provides point-to-point connections for high-speed data transfers. These are far more efficient than the parallel data transfers of older technology, such as ISA. Most modern motherboards include the legacy PS/2 port for connecting a keyboard and mouse, as well as newer connectors such as USB 3.1, which supports up to 40 GBit/s of data.
Processor
The central processing unit, or CPU, is the brain that tells every component in your PC what to do. It processes inputs into outputs, from your keyboard and mouse to your screen and disk drives.
The CPU performs trillions of calculations each second. Its ability to process data faster or slower than other hardware components is what determines overall performance.
Its four primary functions are fetch, decode, execute, and write back. The system clock sends electric pulses to the CPU at regular intervals, and it’s the processor’s job to convert those pulses into instructions.
The arithmetic logic unit (ALU) carries out basic arithmetic operations on numbers, while the floating point unit manipulates numbers more quickly than the ALU circuitry can. The CPU also has registers that store instructions and data. L1 and L2 cache memory let the CPU store information locally, which saves time compared to retrieving it from RAM.
Memory
The built-in main memory (sometimes called internal memory) is made up of chips that can store and retrieve data very quickly. Unlike long-term storage like hard drives and solid state drives, which remember even when the power is off, RAM forgets its contents as soon as the computer switches off.
Depending on the type and job, RAM can process data from twenty to one hundred times faster than a hard disk drive can. It comes in two broad flavors: temporary, volatile kind that forgets as soon as the computer switches off (RAM), and permanent, nonvolatile kind that remembers whether the power is on or off (ROM).
RAM can either be soldered directly onto a motherboard or come in removable modules known as DIMMs that slot into it. Most compact devices go with the soldered-on route for the space savings, but bigger laptops and desktop computers tend to use modular DIMMs.
Graphics Card
The graphics card is the heart of your computer’s visual output. It’s what turns the information your CPU sends it into the image you see on your screen, from spreadsheets to 3D video games.
It starts with geometry processing, where the GPU crunches data sent by the CPU about geometric shapes and their positions in virtual space. It also calculates how light from artificial and natural sources should interact with them.
The GPU’s output is sent to the monitor through a variety of ports, including HDMI, DVI, and DisplayPort. Some high-end cards use multiple 15pin analogue output connections to enable SLI or Crossfire technology. Like other PC hardware, it requires a power connection from the PSU and has a voltage regulation module to control its power draw.
Hard Drive
The hard drive is the home of your computer’s files and programs. It holds pictures, music and text documents, as well as the operating system and application software.
The physical storage component of a hard disk is a series of disc-like objects known as “platters.” Each platter has thousands of subdivisions that can accept an electrical charge. The actuator arm, also called the read/write head, moves across these sectors. When it reaches one, it inscribes it with either a 1 or a 0 — binary code that translates into digital information readable by the computer.
The drive is controlled by a microprocessor and an associative memory stored on a circuit board. The performance of the drive is measured by its data rate and seek time.