4.2 Understanding Computer Hardware
4.2 Understanding Computer Hardware
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Description: Familiarity with the components that go into building desktop and server computers.
Key Knowledge Areas:
Hardware
The following is a partial list of the used files, terms and utilities:
Motherboards, processors, power supplies, optical drives, peripherals
Hard drives, solid state disks and partitions, /dev/sd*
Drivers
Hardware Components of a Computer
Hardware Components of a computer refers to the collection of physical parts of a computer system that we can touch or feel. This includes the computer case, monitor, keyboard, and mouse. It also includes all the parts inside the computer case, such as the hard disk drive, motherboard, video card, and many others. The hardware components of a computer or personal computer is categorized into 4 primary categories:
System Unit
Display Device
Input Devices
External Devices
System Unit
1. System Unit
A System Unit is the main component of a personal computer, which houses the other devices necessary for the computer to function. It is comprised of a chassis and the internal components of a personal computer such as the system board (mother board), the microprocessor, memory modules, disk drives, adapter cards, the power supply, a fan or other cooling device and ports for connecting external components such as monitors, keyboards, mice, and other devices.
2. Display Devices
A display device is a personal computer component and is an output device that enables user to view the text and graphical data associated with a computer program. Display devices commonly connect to the system unit via a cable, and they have controls to adjust the settings for the device. They vary in size and shape, as well as the technology used.
3. Input Devices
An input device is a personal computer component that enables users to enter data or instructions into a computer. The most common input devices are keyboards and computer mice. Input devices can connect to the system via a cable or a wireless connection.
4. External Devices
Any peripherals devices that are not housed inside the system unit are inherently external devices. A personal computer’s functionality can be enhanced by connecting different types of external devices to the system unit, often called peripherals devices. These devices typically provide alternative input or output methods or additional data storage. External devices are connected to the system unit via a cable or wireless connection. Some of them have their own power source and some draw power from the system.
Microphone
Provides audio input
Digital Camera
Provides graphical input
Scanner
Provides graphical input
Speaker
Provides audio output
Printer
Provides printed output
Network device
Provides communication with other computers, such as access to the Internet.
External device
Provides additional data storage
5. System Unit Components
The System Board
Central Processing Unit
Memory
Power Supplies
Cooling Systems etc.
1. The System Board
The system board is the personal computer component that acts as the backbone for the entire computer system as it serves as a single platform to connect all of the parts of a computer together. It connects the CPU, memory, hard drives, optical drives, video card, sound card, and other ports and expansion cards directly or via cables. System Board is also known as motherboard. It consists of a large, flat circuit board with chips and other electrical components on it. Some popular manufacturers of the motherboard are:
Intel
Asus
Gigabyte
Biostar
Msi
2. Central Processing Unit (CPU)
The Central Processing Unit (CPU), sometimes called microprocessor or just processor, is the real brain of the computer and is where most of the calculations take place. Some popular manufacturers / designers of the CPU are:
Intel
AMD
Qualcomm
Media Tek
NVIDIA
Central Processing Unit (CPU) consists of the following features:
CPU is considered as the brain of the computer.
CPU performs all types of data processing operations.
It stores data, intermediate results, and instructions (program).
It controls the operation of all parts of the computer.
3. memory
Memory devices are hardware components that store digital data, categorized as primary (RAM, ROM) for active processing or secondary (HDD, SSD, USB drives, SD cards) for long-term storage, differing in speed, volatility (temporary vs. permanent data retention), and use, from fast volatile RAM for running apps to slow non-volatile drives for files. They work by representing data as binary digits (0s and 1s) using various physical states like voltage, magnetism, or charge. Types of Memory Devices
Primary Memory (Main Memory): Directly accessible by the CPU.
RAM (Random Access Memory): Volatile (loses data without power); used for active programs and data (e.g., DRAM, SRAM).
ROM (Read-Only Memory): Non-volatile; stores permanent instructions like BIOS (e.g., PROM, EPROM, EEPROM).
Cache: Very fast, small memory for frequently used data.
Secondary Storage (Auxiliary Storage): Non-volatile, for long-term storage.
Magnetic: Hard Disk Drives (HDDs), floppy disks, magnetic tapes.
Solid-State: Solid State Drives (SSDs), USB flash drives, memory cards (SD cards, etc.).
Optical: CDs, DVDs, Blu-ray discs.
Key Characteristics
Volatility: Volatile (RAM) vs. Non-Volatile (ROM, SSD, HDD).
Speed: Cache > RAM > SSD > HDD > Optical/Tape.
Storage Capacity: Varies greatly (GBs in RAM to TBs in HDDs).
4. Power Supply
Power Supply known as switch-mode power supply (SMPS) is an electronic circuit that converts power using switching devices that are turned on and off at high frequencies, and storage components such as inductors or capacitors to supply power when the switching device is in its non-conduction state. Switching power supplies have high efficiency and are widely used in a variety of electronic equipment, including computers and other sensitive equipment requiring stable and efficient power supply.
5. Colling System
Cooling may be required for CPU, Video Card, Mother Board, Hard Drive, etc. Without proper cooling, the computer hardware may suffers from overheating. This overheating causes slow downs, system error messages, and crashing. Also, the life expectancy of the PC's components is likely to diminish. The following are commonly used techniques for cooling the PC or Server components:
Heat Sinks
CPU/Case Fans
Thermal Compound
Liquid Cooling Systems
Heat Sinks: The purpose of a heatsink is to conduct the heat away from the processor or any other component (such as chipset) to which it is attached. Thermal transfer takes place at the surface of a heatsink. Therefore, heat sinks should have a large surface area. A commonly used technique to increase the surface area is by using fins. A typical processor heat sink is shown in the figure below:
Fan: The Fan is primarily used to force cooler air in to the system or remove hot air out of the system. A fan keeps the surrounding cooler by displacing air around the heatsink and other parts of the computer. A typical CPU fan is shown below.
Thermal Compound: A thermal compound is used for maximum transfer of heat from CPU to the heatsink. The surface of a CPU or a heatsink is not perfectly flat. If you place a heatsink directly on a CPU, there will be some air gaps between the two. Air is a poor conductor of heat. Therefore, an interface material with a high thermal conductivity is used to fill these gaps, and thus improve heat conductivity between CPU and heatsink.
Liquid Cooling Systems: Like a radiator for a car, a liquid cooling system circulates a liquid through a heat sink attached to the processor. First, the cooler liquid passes through the heatsink, and then gets hot due to transfer of heat from the processor to the heatsink. Then the hot liquid passes through the radiator at the back of the case, and transfers the heat to the secondary coolant (air). Now, the liquid is cool enough to pass through the hot processor heatsink, and the cycle repeats. The chief advantage of LCS (Liquid Cooling System) is that the cooling takes place very efficiently (since liquids transfer heat more efficiently than air/solids). The disadvantages include bulkier cooling system, cost, and additional reliability issues associated with LCS.
Device Drivers
Drivers are used to help the hardware devices interact with the operating system. In windows, all the devices and drivers are grouped together in a single console called device manager. In Linux, even the hardware devices are treated like ordinary files, which makes it easier for the software to interact with the device drivers. When a device is connected to the system, a device file is created in /dev directory.
Most Common types of devices in Linux:
Character devices - These devices transmit the data character by characters, like a mouse or a keyboard.
Block devices - These devices transfer unit of data storage called a block, USB drives, hard drives, and CD ROMs
To list all the device files use the below command:
In the above output, we can see some other types of file types, some of them have B for a block device, C for character device some devices start with /dev/sda or /sdb. etc.
/dev/sd*
In Linux, the disk names are alphabetical. For example, dev/sda is the first hard drive, dev/sdb is the second hard drive, and so on. These devices are mass storage devices like memory sticks, hard drives, etc. Hence, sda means that this device was detected by the computer first.
Example of character device is : /dev/consoles or /dev/ttyS0. These devices are accessed as a stream of bytes.
Example of block device: /dev/sdxn. Block devices allow the programmer to read and write any size of the block. Pseudo devices act as device drivers without an actual device.
Examples of pseudo devices are /dev/null, /dev/zero, /dev/pf
that's all.
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sources:
https://www.geeksforgeeks.org/linux-unix/device-drivers-in-linux/
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