Essay: IT devices and components

The processor is also known as the CPU (central processing unit) is the component that does the most of the work controlling activities of the computer; the efficiency of a processor is measured in Hertz, meaning the frequency of cycles. The more Hertz a processor has the more tasks it can do at once.
In contemporary personal computers; there are several cores e.g. Quad core processor
A processor core is a separate processor unit, the more cores a computer has; the greater the processing power.
In addition to this graphics processor unit (GPU) is just like a CPU except it is specifically for the graphics card.
Graphics cards
Graphics cards control the output display on the PC monitor(s).
The types of cards are;
• Cooling cards are graphics cards have their own heat sink and fan right on top of the graphics processing unit to keep it cool.
• Power Draw cards are video cards tend to use lots of energy, due to this it may need an extra power supply.
• On-board graphics cards are built into a computer’s motherboard in a slot.
•Dedicated cards are graphics cards that are installed in slots, and have their own video memory separate from main RAM.
• Multiple Cards; 2 or more graphics cards installed into the motherboard to increase processing power.
RAM (random-access memory) is a temporary memory. Files that are in constant use are held in the RAM, while the computer is on.
Unlike ROM, RAM is volatile; meaning that RAM can be changed. Once the computer is powered down; the memory on RAM is lost.
RAM works by using binary. This works by using magnetic switches on the component being on or off (1 or 0), a switch is called a bit and these are divided into eight (8-bit/byte) for a command. In RAM the switches are constantly changed, this is done by magnetising and demagnetising the switches in the RAM component.
If you choose to save the memory in RAM, the memory would be saved onto the hard disk.
In modern graphics cards; VRAM on the processor is used rather than RAM, however when the processor does not have VRAM, the RAM is utilised. The drawback of using RAM instead of using a dedicated VRAM is that using RAM for graphics in games for example: there would be a slower frame rate, pop-ins and overall lower quality of graphics as the distance between RAM and CPU is longer than the distance between VRAM and the CPU
Flash Drive
Flash drive is a removable non-volatile storage (keeps memory when turned off)
Optimal writing rate for a USB 3.0 is 46 MB/s
Optimal reading rate for USB 3.0 is 68 MB/s
Flash drives are used to transfer files to different devices and the USB is good at this, because unlike a hard disk drive, it does not have moving parts, because it is a solid state drive. In addition to this unlike other devices, flash drives do not need device drivers due to the USB mass storage device class meaning that data can be transferred to contemporary operating systems (Microsoft, Ubuntu, Mac OS) without the use of a device driver.
Cache Memory
Cache memory is when an instruction is saved onto RAM, when the instruction is used frequently. When a processor is going to read data it scans the cache to see if a duplicate of the data is there to read, this makes it faster to read than reading from the hard-disk.
Editing Software
PhotoShop is popular Bitmap editing software for advanced editors; you see this software used in editing of images in magazines, advertisements and photography. You will also see this software when architects render their building designs.
Microsoft Paint is Bitmap editing software that comes with each copy of Microsoft (MS 95, XP, 7, 8 etc.); Paint is for beginners, who are novice editors as Paint provides limited editing tools compared to Photoshop.
Fireworks is a vector based editing software, vector means that the resolution of the image stays the same even if you change the size of the image, due to this you have to use polygons unlike Bitmap you cannot ‘freehand’ edit images, you have to manipulate using the polygon tools in order to get the desired image.
Input devices
Computer Monitors are the output for the graphics card, and originally used CRT (Cathode Ray Tube) and in recent years more commonly used LCD (liquid crystal display) as it is of higher quality and saves more space. The disadvantages of CRT are:
Radiation is emitted through the screen
Damage to monitor when used for prolonged amount of time (burn-in)
More than 2x the power required than LCD
Due to these disadvantages LCD monitors are more commonly used.
Mobile touch screens work by a plastic film on top of a layer of glass when you make contact with the plastic (apply pressure), the circuit is completed so it shows interaction on-screen such as entering an application, swiping the menu or playing a game.
Output devices
Printers
Laser Printer: Invented in 1969. As the name suggests this printer uses lasers on the drum that creates static electricity on the paper that is used to put toner onto the paper via the toner hopper. This is ideal for printing off word processing.
Inkjet Printer: Invented in 1951. This uses coloured small ink droplets from the cartridges onto the paper. Inkjet printer takes substantially longer than a laser printer due to this process. Lately this has grown in popularity. This is ideal for printing off images.
Laser Printers with large documents are faster and more efficient with larger documents than Inkjet. However the colour cartridges for Laser printers are more expensive.
For images today, Inkjet is commonly used, because it prints quickly for small images and to a high quality, however ink cartridges are have to be frequently replaced.
Scanners are used if you want to put images onto the computer; this is the earliest form and image/text capture for the PC.
Keyboard is used to as an input device for the computer. A keyboard works by a non-mechanical membrane triggers producing letters and numbers on the monitor as it is transferred as binary to the computer, which appears as letters and numbers on-screen.
Mouse is used as a pointer on the screen to interact with GUI, is this done by the left bumper on the mouse to ‘click’ and the right bumper for options menus then the information is sent as binary similar to the keyboard