The central or core processing unit (CPU) and the random access memory (RAM) are two of the most important components of your computer.

Though their roles are vastly different, they work together to give your computer the functionality and performance you rely on for everyday tasks like running software or browsing the web. Understanding the difference between CPU and RAM can help you build or buy a computer that is futureproofed and perfectly suited to your needs.

In this article, we pop the hood on your computer to examine what the CPU and RAM are, their roles, and how they can influence your computer’s performance. 

What is the CPU?

The central processing unit (CPU) is a semiconductor component that contains electronic circuitry for executing the instructions provided by a computer program. It is also known as:

  • A core processing unit
  • Main processor
  • Central processor
  • Processor

The CPU is almost always in the upper area of a computer’s motherboard. It is installed pins-down onto a dedicated CPU socket and secured by a small lever. It is located in the upper area to ensure that it is well-ventilated as it generates a lot of heat and could become vulnerable to thermal damage.

The intricate circuits of a CPU perform the computations specified by an operating system or software program electronically, including:

  • Logic
  • Basic arithmetic 
  • Controlling 
  • Input/output (I/O) operations

Every CPU, irrespective of size or form, executes sequences of instructions that are packaged as a program and stored in some form of memory. CPUs follow an instruction cycle that comprises fetch, decode, and execute steps.

CPUs components include: 

  1. An arithmetic–logic unit (ALU) that performs arithmetic and logic functions of the computer 
  2. A variety of processor registers supply instructions to the ALU and store data from ALU operations
  3. A control unit that directs the acquisition of data from the memory, the execution of instructions, and coordination of the processor registers and other relevant components.

In modern computing, the CPU is part of an integrated circuit (IC) microprocessor. These computer chips, or processor cores, may contain multiple CPUs running in parallel in accordance with the specification and performance of the computer. Along with the CPU, an integrated circuit may also include memory, and interfaces for other components to become a system on a chip (SoC).

A Brief History of CPU

The history of the CPU is the history of computing and traces its transition from a mechanical to an electrical and then an electronic component for the execution of calculations. Here are the major events in the development of the modern CPU: 

  • The discovery of the element silicon (Si) by Baron Jons Jackob Berzelius was critical to the development of the semiconductor technology that is used to make processors. 
  • By 1903, Nikola Tesla had developed electrical logic circuits called “gates” or “switches.”
  • In the early 1950s, computers were large completely custom-built machines. The processing elements had to be completely hand-wired just to complete a single task required by a program.
  • In the late 1940s and early 1950s, the English electronics engineer, Geoffrey Dummer, conceptualized and built a prototype integrated circuit.
  • Robert Noyce of Fairchild Semiconductor (later Intel) and Jack Kilby of Texas Instruments developed the first working integrated circuit, demonstrating it on September 12, 1958. 
  • In 1968 Robert Noyce and Gordon Moore founded Intel Corporation. They released the 8008 processor on the 1st of April, 1972.
  • Two years later, Motorola released the MC6800, which was an 8-bit processor with a 1-2 MHz clock frequency. By 1982, National Semiconductor developed the first 32-bit general used processor. 
  • Apple, IBM, and Motorola formed the AIM Alliance and developed a 32-bit processor for personal computing known as the PowerPC 601.

Microprocessor Technology

Microprocessors have been essential to the rapid evolution of the CPU. Microprocessor technology sped up the advancement of computing because it could apply it to a variety of commercial and industrial applications and was capable of mass production, reducing production costs.

These computer processors are digitally integrated clock-driven circuits. Despite their small scale, they contain the arithmetic, logic, and control components of a CPU, making the microprocessor capable of interpreting and executing instructions from a program. 

What is RAM?

RAM stands for random access memory, a volatile computer memory format that can be rapidly read and written in any order (randomly). Like the CPU, RAM is made from semiconductor technology, storing working data and temporary files in its electrical circuits for use by the CPU, GPU, or other components. 

RAM tends to be the main type of working memory in a computer. It differs from non-volatile storage components like hard-disk drives or solid-state drives as it works faster and cannot retain data after its power supply is cut off.

RAM in the motherboard
Your computer’s RAM is necessary for the short-term memory storage of immediate tasks.

A Quick History of RAM

The development of RAM has also contributed to advancements in the speed and performance of personal computing. Memory functions were originally executed using mechanical counters rather than electronic circuits. Here are some of the highlights of the development of RAM technology: 

  • The Williams–Kilburn tube (1947) is thought to be the earliest known form of RAM. It was a cathode ray tube that stored data as electrically charged spots.
  • Magnetic-core memory was also developed in the late 1940s, a product of the work of Frederick Viehe. This form of memory stored data using metal rings, each capable of storing one bit of data and connected with wires.
  • It would take several decades to progress to solid-state memory. This was invented in 1968 by Robert Dennard and could store multiple bits of data. 
  • RAM would later become synchronized with computer processors in the late 1990s, unleashing increased processing power and speed. 
  • In the early 2000s double data rate RAM was developed which massively enhanced processing speeds with a favorable reduction in power consumption. 

Along with the CPU, you’ll find RAM installed on a computer’s motherboard. It is connected via Small Outline Dual In-line Memory Module (SODIMM) slots that are near the CPU. In this position, the RAM can acquire hard-drive data for the CPU to use. If the data held is no longer required, or the computer is switched off, the RAM is wiped.

What’s the Difference Between the CPU and RAM?

Though CPU and RAM both use semiconductor technology, they are entirely different computer components. The CPU delivers the processing power and coordination that enable the computer to perform its operations. Its central role means that it can determine the speed at which the computer completes its tasks. The more powerful and advanced your processor is, the faster the computer is able to think and work.

The computer’s RAM is subordinate to the CPU. As the CPU executes the tasks directed by the program or application that is running, the RAM is loaded with the data that needs to be ready for the CPU to use. The RAM is easier and quicker for the CPU to access than the hard drive or storage devices.

CPU is often far more active than RAM. When the CPU usage is at 100%, the RAM may only be at 50%; the CPU has a far greater workload. 

RAM vs. VRAM: A Side-by-Side Comparison

CPURAM
What it isA semiconductor processorMemory chip
Primary UseExecution of the calculations and operations dictated by a computer programStorage of temporary system files
Initial ReleaseSeptember 12, 19581970
Influential DevelopersRobert Noyce, Jack Kilby, Gordon Moore, Intel Freddie Williams and Tom Kilburn, Frederick Viehe, Fairchild Semiconductor, Intel 
Technologies InfluencedMicroprocessors
System-on-a-chip
Virtual CPUs 
Clockless CPUs
DRAM, SRAM, RDRAM, DDR SDRAM, and VRAM

Similarities and Differences

Similarities

  • Both CPU and RAM use semiconductor technology
  • RAM and CPU consist of integrated circuits.
  • Both the CPU and RAM are essential for the normal operation of a contemporary computer or laptop.
  • The CPU and RAM are both located on the motherboard.
  • RAM and the CPU can both store data. The CPU stores data it is working on in its registers that have much less capacity than RAM.
  • Intel was an influential developer of both RAM and CPU.
  • Both the CPU and RAM can be removed and upgraded from a typical PC motherboard.

Differences

  • The CPU and RAM occupy distinct positions on the motherboard.
  • RAM is a memory chip, and the CPU is a microprocessor.
  • RAM is composed of memory cells, CPU consists of a control unit (CU), an arithmetic logic unit (ALU), cache, buses, a clock, and a variety of registers.
  • The CPU executes instructions, and the RAM stores data temporarily.

What is the CPU Used For?

The CPU is the brain of your computer and provides the processing power that is necessary for the computer to perform its operations. It retrieves and executes the instructions provided by computer programs, processing arithmetic, and logic operations in accordance with the program’s requirements. The controller, which also controls the exchange of signals and data with the processor’s various interfaces, moves the computer’s data within the CPU. The CPU has its own working storage in the form of registers that hold instructions, record processes, and store addresses. 

The processor also has a clock which is used to synchronize its component. Its speed is measured in megahertz (MHz) and determines the speed at which the CPU processes data. In modern computing, the RAM is synchronized with the CPU clock for increased speed and efficiency. 

Does the CPU Need to be Upgraded?

Many people think that RAM is key to enhancing the speed and performance of a personal computer. However, the gains of increasing the amount of RAM can only be realized with a fast and powerful processor.  

Upgrading the processor delivers massive increases in the speed at which your computer can complete tasks. If partnered with increased RAM capacity, you can achieve a marked uplift in speed.  

CPU vs. RAM: 6 Must-Know Facts

  • CPU stands for the central processing unit.
  • RAM stands for random access memory.
  • CPU and RAM are semiconductors that use integrated circuits to store and move data.
  • The processor uses RAM to store data it uses temporarily.
  • RAM is connected to the CPU via the front-side (FSB) or system bus.

Final Thoughts

The processor is the control center of your computer and coordinates and executes the functions that make it work. It relies on RAM to hold the data it needs to complete its operations.

The close relationship between the CPU and RAM means that upgrading either component will enhance the performance of your computer. However, improving the speed and processing power of the CPU can deliver greater performance gains as this component determines how fast your computer solves problems.

CPU vs. RAM: Understanding the Differences FAQs (Frequently Asked Questions) 

What is the ‘fetch’ operation?

Fetch is the first part of the CPU’s instruction cycle. It involves getting instruction in numerical form from the program memory. Sequences of instruction, known as an instruction set, are represented by numbers. Each number identifies the next instruction in the sequence.

If the CPU fetches instructions from slow forms of memory, this may delay the CPU, which pauses while the retrieval takes place. The CPU uses RAM and caches to help speed up the fetch process.

What is the ‘decode’ operation?

The next stage of the CPU’s instruction cycle is decoding. The instruction comprises multiple fields: the opcode that denotes the operation that is required, and supplemental information (including memory addresses and processor registers), known as operands. The CPU contains an instruction decoder which is binary decoder circuitry that converts the numerical instructions into signals that communicate with other parts of the processor.

What is the ‘execute’ operation?

Execute is the third step of the CPU’s instruction cycle and can comprise one or multiple actions. Sequences of electrical signals enable or disable circuits within the CPU so that it performs the actions required. The clock pulse usually synchronizes the actions, meaning that a higher frequency CPU will execute its tasks more frequently. The results of actions are often held in the CPU’s internal registers or written to the RAM.

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