Difference Between Von Neumann and Harvard Architecture

By Anjnee Bhatnagar|Updated : September 30th, 2022

The Difference between Von Neumann and Harvard Architecture is that in Von Neumann, the same physical memory is used, whereas, in Harvard Architecture, different and separate physical memory is used for storing data. While learning computer organization, we came across two types of computer architecture: Von Neumann and Harvard architectures developed by Jon Von Neumann and Harvard Mark.

Difference Between Von Neumann and Harvard Architecture

This article will deal with the difference between Von Neumann and Harvard Architecture. Generally, any microcontroller is an arrangement of CPU components, specifically RAM and ROM. Von Neumann and Harvard architecture have different arrangements for memory and data, which is the basis of the difference between Von Neumann and Harvard Architecture.

Difference Between Von Neumann and Harvard Architecture

In Von Neumann's design, the programs and data are stored in the same memory space and treated as one. We will see the difference between Von Neumann and Harvard Architecture based on metrics such as speed, performance, etc, which will help clarify doubts regarding these architectures for the GATE exam preparation.

Key Differences Between Von Neumann and Harvard Architecture

Von Neumann Architecture

Harvard Architecture

The same physical memory is used to store instructions and data.

Separate physical memory is provided to store instructions and data.

It is based on the stored-program concept.

It is based on relay-based computer models.

Common bus for transferring instructions and data.

Separate buses are used to transfer instructions and data.

Two clock cycles are used to execute a single instruction.

A single clock cycle is used to execute a single instruction.

It is cheaper in comparison to Harvard architecture.

It is more expensive than Von Neumann’s architecture.

Used in personal computers.

Used in microcontrollers and signal processing.

Von Neumann and Harvard Architecture

Von Neumann's architecture was designed by renowned mathematician and physicist John Von Neumann in 1945. Harvard Architecture originated from relay-based computers that stored data in electro-mechanical counters and instructions on punched tapes. Both architectures hold an important weightage in the GATE CSE syllabus.

What is Von Neumann Architecture?

The computers are based on the stored-program concept. A stored program keeps data and program instructions in RAM, where instruction fetch and a data operation cannot occur simultaneously.

This process is referred to as the Von Neumann bottleneck. Due to this bottleneck, the performance of Von Neumann’s architecture is limited. The Von Neumann architecture is as follows:

Difference Between Von Neumann and Harvard Architecture

What is Harvard Architecture?

This microcontroller design has separate storage areas and signals for instructions and data. The basic difference between Von Neumann and Harvard Architecture is the contrast in the storage area for instructions and data. Unlike Harvard, Von Neumann has the same storage unit for programs and instructions. However, modern processors use Von Neumann microcontrollers.

The Harvard architecture is as follows:

Difference Between Von Neumann and Harvard Architecture 2

Related GATE Topics 
Difference between impact and non-impact printersDifference between Java and Core Java
Difference between input and output devicesDifference between linker and loader
Difference between internet and intranetDifference between mixture and compound
Difference between internet and wwwDifference Between Algorithm, Pseudocode, and Program

Comments

write a comment

FAQs on Difference Between Von Neumann and Harvard Architecture

  • Apart from the hardware arrangement, there is a difference between Von Neumann and Harvard Architecture based on speed. The Von Neumann architecture works faster than the Harvard architecture as both the instructions and data are present in the same storage unit.

  • Computers are divided into two types based on their architectures and arrangements of CPU, basically RAM and ROM:

    • Von Neumann Architecture
    • Harvard Architecture

    In Von Neumann architecture same storage unit is used for data and instructions, while in the Harvard architecture separate storage area is used for instructions and data. Due to the same storage space in Von Neumann, the speed of executing programs is fast.

  • Historically, the computers are divided into two types:

    • Fixed program computers
    • Stored program computers

    In fixed program computers, one cannot change the control signals and alter the circuit as per requirement. These functions cannot be programmed. Example: calculator. While in the Stored program, functions can be programmed differently to obtain the desired output.

  • A stored program is a manner of storing the instructions and data simultaneously in the same storage area. The Von Neumann architecture follows this concept of the stored program, while another architecture called Harvard architecture, in contrast, uses the relay-based computer model.

  • A CPU or central processing unit is the heart of the computer. A CPU is responsible for processing the inputs and generating the outputs. It consists of three components called the ALU unit, Registers, and the Control Unit. The arrangement of memory elements of the CPU leads to the two architectures called Von Neumann and Harvard.

  • The difference between Von Neumann and Harvard Architecture based on clock cycles is that in Von Neumann architecture, there are two clock cycles whereas, in Harvard architecture, there is only one clock cycle.

Follow us for latest updates