What is CPU?
CPU(Pronounce: C-P-U; Central Processing Unit), also known as "Brain of Computer" and sometimes be called "Microprocessor", it processes instructions that are gather from decoding the code in files and programs.
Part of CPU
There're 3 part of CPU, which are ALU, Control unit, and Register.
ALU
Is a digital circuit that calculates an arithmetic operations and logic operations between two numbers. The ALU is a fundamental building block of the central processing unit of the computer.
Control Unit
Control CPU operation, including ALU operations, the movement of data within the CPU, and the exchange of data.
Registers
These components are special memory locations that can be accessed very fast. Three registers that are shown:
- The Instruction Register (IR)
- The program Counter (PC)
- The Accumulator
CPU Functions
CPU has 4 main functions, which are fetch, decode, execute and writeback.
Fetch
Is the first step of all functions, when the user makes a command to open the program, the CPU receive the request and process it. The CPU then retrieves the desired program by accessing memory for the program's location. Each program has a program counter number, this is a roadmap that the CPU uses to locate the program and get further instructions from the program.
Decode
When CPU fetches the program, it doesn't see all of graphical aspects like how user see them, but see the code instead. The code must be deciphered into a language that CPU able to read and understand. There are literally hundreds of different programming languages that programmers use to write software programs. First the CPU must decide what language the program is written in and then decode it so that it understands the instructions that are held inside the code.
The decode process is another list of steps. The CPU breaks down the code so that it is manageable. The part that the CPU deals with are the only ones that directly communicate with it. The opcode(indicates the numerical order of code) is used to figure out the order in which the code must be executed.
There are times when a CPU can't interpret the code on its own, so it uses a translator called a microprogram. Once the microprogram has interpreted the code, it sends the instructions back to the CPU in a language that it understands.
Execute
After the CPU finding the numerical order of the instructions in the code, it's now ready to execute them. The program is loaded and made ready for the user. All the components necessary for the program to run efficiently are loaded using the opcode and microprogram if necessary.
Writeback
Is the final step of all functions. During the each previous functions, the CPU records feedback on the process, this function is necessary if there was a problem during one of the functions. Even if everything loaded successful, the CPU writes the status back into melody. An example of this is when an error causes Windows to not start properly.
Type of CPU
Single core
Single core CPUs are the oldest type of Computer CPU available and initially, this was the only type of CPU that could be used in Computers. Single core CPUs can only start one operation at a time, so they were not very good at multi-tasking. This meant that there were noticeable deceases in performance whenever more than one application was running. Although only one operation could be started at a time, another one could be activated before the first one was finished.
Advantages
1. Use less power, it takes less power to run a single core CPU. Dual core and Quad core use up a lot of energy, which is not a problem with machines that are plugged into the wall, but it can drain the laptop batteries quickly.
2. Run coolers, using less power mean there's less heat generated by the core.
3. Sufficient for most software, much of today's software isn't build for multi core.
Disadvantages
1. Run slower - In cases where the Computer specs are comparable.
2. Freezing - Many of today's software programs use up a lot of computing power. Often, a user will use many programs, which overloads the CPU.
Dual core
A dual core is a single CPU that has two cores and thus functions like two CPUs in one. Unlike single core CPUs where the processor has to switch back and forth between different sets of data.
Advantages
1. Perform tasks faster - Dual-core CPU run faster than single-core ones, especially in instances where there are multiple processes at one time.
2. Reduce costs - Even before there were dual-core CPUs, users were able to build dual-processor units that had the computing power of two computers.
Disadvantages
1. Wasted computer power - While dual-core CPUs certainly can blaze through numerous applications, most regular users don't need that much power.
2. Compatibility - Dual-core CPUs will run any software of course, but the software itself has to be programmed for dual-core CPU.
Quad core
Quad core CPUs are a further refinement of the multi-core CPU design.
Advantages
1. Multitasking - The quad-core system is one of the best systems for multi-tasking.
2. Run intensive applications - Applications that use up a lot of resources, such as graphics programs, video editors, and anti-virus programs can run smoothly at the same time.
3. Less heat and power consumption - Most of the newer quad-core chips are so small and efficient; they can actually use less power and generate less heat than single-core systems.
4. Use for a long term - The problem with Moore's Law is that it practically guaranteed that your Computer would be obsolete in about 24 months. Since few software programs are programmed to run on dual-core, much less quad-core, these processors are actually way ahead of software development.
Disadvantages
1. Lowers battery life - Depending on the type of applications, quad-core system can drain batteries faster.
2. Available software - Software needs to be programmed to take full advantage of quad-core CPUs, so not all programs can utilize the four processors.
3. Hardware compatibility - Multi-core processors are compatible with certain motherboards, so it's not as simple as swapping out the old CPU with a brand new one. Purchase of a new motherboard may also necessitate the purchase of other components that are compatible with the motherboard.
Some type of Intel CPU
Intel Pentium Dual Core Processors
The Intel Pentium processors with Intel dual-core technology deliver great desktop performance, low power enhancements, and multitasking for everyday computing.
Intel i3 Processors (Ivy Bridge)
Intel core i3 dual core processors provide 4-way multitasking capability, runs at fixed speed ideal for typical tasks and media playback but not games.
Intel i5 Processors
Intel i5 usually quad core but some dual processors deliver the next level of productivity. Mostly the same as i3 but with Intel Turbo Boost Technology, delivers extra speed when you need it, like the i3 integrated graphic is included but is only ideal for normal use, not for gaming.
Intel i7 Processors
Intel i7 Processors dual or quad core for the most demanding applications with cache and faster clock speeds, quad-core processors feature 8-way threading, four cores will run faster, and more L3 cache, but will consume more power. High-end use, video and gaming with dedicated video card.
