Difference between CPU and RAM
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If you are wondering whether to invest in a new computer system or smartphone, then you have to understand the functioning of the central processing unit (CPU) and the Memory (RAM – Random Access Memory). The CPU and RAM are the two important parts of electronic gadgets. The CPU handles the functioning of the device and memory stores that functions command. They both are quite dependent on one another, but in technical terms, they are entirely different from each other. So, today we are going to establish the systematic difference between the central processing unit (CPU) and Random Access Memory (RAM).

CPU carries out all the requests and calculations based on input, where RAM stores the requests and data required by the CPU.

What is a Central Processing Unit (CPU)?

Central Processing Unit (CPU)
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The CPU is a part of the hardware that carries forward the instructions of a computer program. It is trained to perform basic functions like arithmetic, logic and input/outfit operations in the computer system. In the computer, every instruction goes through the CPU, it doesn’t matter how small it is.

A CPU has multiple components which perform different work. It has an arithmetic logic unit that has a responsibility to perform simple arithmetic and logical tasks. It also contains a control unit that handles the various parts of the computer. It has the responsibility to read and interprets instructions from memory and convert them into a series of signals to start the operations of the other computer parts. The control unit also calls the arithmetic logic unit to perform the necessary calculations from time to time. In CPU operations, cache memory is used which is high-speed memory where instructions can be copied and retrieved quickly.

The CPU contains at least one processor, which is the actual chip inside the CPU that performs calculations. A CPU with two processing cores is called a dual-core CPU and models with four cores are called quad-core CPUs. High-end CPUs may have six (Hexa-core) or even eight (octa-core) processors. A computer may also have more than one CPU, which each have multiple cores.

  • 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.

A CPU executes an instruction by fetching it from memory, using its ALU to perform an operation, and then storing the result to memory.” Via wikipidea

RAM (Random Access Memory)

Random Access Memory
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RAM also known as computer memory unit is that part of the computer hardware which handles all the memory and caching related operations of the processor. It has two separate registers that are managed by the CPU’s control unit. Data to be sent to the main memory or retrieved from memory is stored in the Memory Data Register (MDR). The desired logical memory address is stored in the Memory Address Register (MAR). The address translation is also known as address binding and it uses a memory map that is programmed by the operating system.

The two main types of RAM are:

  • Dynamic Random-Access Memory (DRAM)
  • Static Random-Access Memory (SRAM)

The difference between SRAM and DRAM are in how they refresh, or speed. SRAM is faster because DRAM needs to refresh quite often (thousands of times per second) whereas SRAM doesn’t.

In terms of seconds, DRAM gives access times of about 60 nanoseconds. SRAM does the same in 10 nanoseconds. Since the speed difference is so great, one would expect SRAM to be the most common type of RAM, but it’s not because it’s quite expensive.

What is the relationship between CPU and RAM?

 RAM (Random Access Memory) is an asset for the CPU (Central Processing Unit) to complete its tasks. If the CPU is a nail gun, RAM are nails. As the CPU processes tasks, runs applications, it needs/uses memory.

When a computer system performs a certain task like rendering a video for a game or calculating numbers to add in the spreadsheet, then a certain series of instructions are needed to be processed by the central control unit. The number of instructions run by the processor can be measured in megahertz which means millions or billions of instructions can be processed per second.

Numerous modern processors have multiple cores nowadays, which means sub parts that are capable of running different programs and components of the programs in the parallel line.

On the other hand, to smoothly run operations, most of the programs required a certain amount of memory to store the working data. The data can rotate back and forth on the disk, but that takes lots of time and can slow down the efficiency of the program. It can reduce the performance of the program drastically.

So, this process of central processing unit and memory clearly defines that to smoothly run the operations of a computer system –  compatible CPU and memory are required.

Features of CPU (Central Processing Unit)

  1. CPU has cache memory which is located inside the processor to make access to the main memory fast. This memory fetches information from the main memory and reverts to the CPU for processing.
  2. These days CPUs are designed with multiple cores. The cores work independently within the CPU and are used for processing the parallel data to increase the overall efficiency of the computer for the management of the work.
  3. The speed of the central processing unit is measured in gigahertz or megahertz. Hertz is the frequency of the unit. The processor which has more frequency is capable of performing work with a higher speed.
  4. The latest generation of processors has multithreading support due to parallel processing. In multithreading, two logical cores exist in each core of a CPU which works in parallel.
  5. A good processor should support different memory modules such as DDR1, DDR2, and DDR3 and it should be compatible with the motherboards designed by different companies.

Features of RAM (Random access memory)

  1. Memory has the responsibility to handle different locations in the computer system. There are three main locations that memory has in the device – CPU in the form of registers, main memory like RAM or ROM, external memory such as hard disk, CD, DVD, pen drive, etc.,
  2. The maximum number of bits defines the memory. In case of the internal memory, it is equal to Word size, but in external memory, it is often larger than the word size.
  3. Memory can be accessed in three different ways. Random access is the memory that can be accessed in any order and the access will be independent of the memory location. Serial access memory can be accessed in a certain predetermined sequence only. Semi-random access memory devices use this access like a hard disk.
  4. The performance of the memory is determined using three parameters -access time, memory cycle time and transfer rate.
  5. Memory devices can be physically distinguished into two types – semiconductor memory like RAM and magnetic surface memory like a hard disk.


It is clear as daylight that CPU and memory are an integral part of the computer system. They both are highly important for the working of electronic gadgets. They might have different features, but their functioning is interlinked. So, when purchasing a new gadget, make sure that the central processing unit and memory are powerful.

Steve Ballmer
With over 7 years of experience in the IT industry, I have experience in IT support, helpdesk, sysadmin, network admin, and cloud computing. Certified in Microsoft Technologies (MCTS and MCSA) and also Cisco Certified Professional in Routing and Switching.