Difference between Von Neumann and Harvard Architecture

Computer ProgrammingData StructureDifferences

There are two distinct varieties of digital computer architectures, each of which provides a description of the functioning and execution of computer systems

  • The first is known as the Von Neumann Architecture, which was designed by the well-known physicist and mathematician John Von Neumann in the late 1940s.

  • The second is known as the Harvard Architecture, which was based on the original Harvard Mark relay-based computer and used separate memory systems to store data and instructions. Both of these computer architectures were developed in the 1950s.

In the original Harvard architecture, data and instructions were both stored in electro-mechanical counters, while the instructions were punched into tape. Modern computing is predicated on the Von Neumann architecture, which also has the advantage of being simpler to put into practise.

This article takes a detailed look at both of these computer architectures and highlights the points that differentiate them.

What is Von Neumann Architecture?

This is a hypothetical architecture that is derived from the idea of stored-program computers, in which the memory is used for storing both the program data and the instruction data.

  • Prior to the introduction of the Von Neumann idea of computer design, computing machines were developed for a single predetermined function, and their level of sophistication was limited as a result of the need for human rewiring of the circuitry.

  • The ability to keep instructions in the memory along with the data that the instructions operate on is the central tenet of the Von Neumann architectures.

  • In a nutshell, when people talk about the Von Neumann architecture, they are referring to an overarching structure that the hardware, programming, and data of a computer should adhere to

Components of Von Neumann Architecture

There are three major components that make up the Von Neumann architecture. These components are the CPU, the memory unit, and the I/O interfaces.

  • The control unit (CU), the Arithmetic and Logic Unit (ALU), and the registers make up the other two main parts of the CPU, which serves as the beating heart of the computer system.

  • The arithmetic and logic operations on data are the responsibility of the ALU, whereas the control unit is responsible for determining the order of flow of instructions that need to be executed in programs by issuing control signals to the hardware. The ALU is responsible for carrying out all of these operations.

  • The registers are essentially short-term storage sites that are used to hold the addresses of the instructions that have to be carried out. RAM, or Random Access Memory, is the primary memory that is used to store program data and instructions. The memory unit consists of AM. Users are given the ability to communicate with the outside world, such as storage devices, by means of the I/O interfaces.

What is Harvard Architecture?

It is a type of computer architecture that keeps programme data and instructions in storage and signal channels that are physically independent from one another.

  • In contrast to the Von Neumann design, which retrieves instructions from memory using a single bus while simultaneously moving data from one component of a computer to another, the Harvard architecture keeps data and instructions in their own distinct memory spaces.

  • Both ideas are comparable, with the exception of the means through which they access memory. The Harvard architecture is based on the concept of separating the memory into two distinct sections, with one section dedicated to storing data and the other to storing programmes. The concept was derived from the first Harvard Mark relay-based computer, which used a technology that enabled simultaneous execution of data transfers, instruction fetches, and both types of data transfers. The word was named after this machine.

  • Real-world computer designs are really based on a modified version of the Harvard architecture, which is frequently utilised in digital signal processors and microcontrollers (Digital Signal Processing).

Comparison between Von Neumann and Harvard Architecture

The following table highlights the major differences between Von Neumann and Harvard Architecture −

Basis of Comparison
Von Neumann

Harvard Architecture
The Von Neumann architecture is a style of computer architecture that is straightforward and makes use of a single memory connection.The Harvard Architecture is the current design standard, and it features RAM and ROM that are kept completely independent.
The layout is straightforward and makes use of the same path to both store data and take instructions.When compared to the Von Neumann architecture, this design is more complicated because it utilises separate connections for RAM and ROM.
When compared to Harvard Architecture, the hardware requirements are significantly lower.When compared to the Von Neumann Architecture, the Harvard Architecture places a greater emphasis on the use of hardware.
In comparison to the Harvard Architecture, the speeds of the processors are significantly lower.Harvard Architecture is faster than the others. A computer modelled are significantly lower. after the Harvard Architecture calls for an increase in the available space.
Physical space
When compared to the Harvard Architecture computers, the Von Neumann computers have a smaller footprint in terms of the required amount of physical space.In Harvard Architecture, the requirement for the actual space is increased.
Internal memory
Because the memory and the programmes share the same space, there is no unused space in the internal memory.Because the instruction memory and the data memory cannot share the same space, some of Harvard's internal memory is going to waste somewhere.
Running Instructions
The instructions for running can either be taken from the programme that has been stored or they can be given explicitly. As a result, the two cannot be considered together.Due to the fact that the input and the programme instructions that are stored in the programme are taken simultaneously, the running instructions are somewhat complicated and somewhat slow.


Von Neumann and Harvard are both known for their contributions to the field of computer architecture. They are the antithesis of one another in every way. When compared to the Von Neumann, the Harvard computers necessitated more storage space but were significantly faster.

The Von Neumann algorithm is straightforward and makes use of the same processing unit for both the instructions and the programs, whereas the Harvard algorithm is more complicated and uses separate processing units for each type of data. Every element of the Von Neumann Architecture is a direct contrast to the style of Harvard Architecture.

Updated on 29-Jul-2022 09:05:50