Difference between Von Neumann and Harvard Architecture
Last Updated :
18 Dec, 2024
Von Neumann and Harvard architectures are the two basic architectures in the field of computer architecture to explain the way of memory and process units in a computer system. For those people who are engaged in Computer Science or trying to work in companies providing computing technologies, it is necessary to recognize the peculiarities of these architectures. There are supposedly two models of multiprocessing architectures distinguished: Von Neumann and Harvard architectures While the former occupies a dominant position, its principal differences from the latter, advantages, and disadvantages will be discussed in this article to provide you with information on which structure is more fitting for a given application.
Von Neumann Architecture
Von Neumann Architecture is a digital computer architecture whose design is based on the concept of stored program computers where program data and instruction data are stored in the same memory. This architecture was designed by the famous mathematician and physicist John Von Neumann in 1945.
Advantages of Von Neumann Architecture
- Simplicity: The fact that all data and instructions are stored in a single memory space helps the process of designing a computer system as there is no need to create complicated systems of routing since pathways may coincide.
- Cost-Effective: A smaller number of components is needed as compared to the other architectural designs hence more economical.
- Flexibility: A program can Always be changed or altered without experiencing a change in some underlying physical aspects such as the circuitry.
Disadvantages of Von Neumann Architecture
- Bottleneck Issues: The shared bus can be a problem because the data and control instructions cannot be obtained simultaneously and therefore it becomes slow.
- Memory Corruption: Since the data and instructions reside in the same memory, then there is a temptation of one erasing the other thereby producing system faults.
Harvard Architecture
Harvard Architecture is the digital computer architecture whose design is based on the concept where there are separate storage and separate buses (signal path) for instruction and data. It was basically developed to overcome the bottleneck of Von Neumann Architecture.
Features
- Separate memory spaces
- Fixed instruction length
- Parallel instruction and data access
- More efficient memory usage
- Suitable for embedded systems
- Limited flexibility
Advantages of Harvard Architecture
- Faster Processing: The availability of two buses for data and instructions avoids a problem of contention where only one bus is used and this enhances the velocity of the system.
- Improved Security: In this way the chance of memory corruption is at least cut in half since data is not stored in the same locations as instructions.
- Efficient Use of Resources: It enables the use of different memory for data and for instructions of different sizes as this help in optimal utilization of the buses and other resources.
Disadvantages of Harvard Architecture
- Complexity: The design and the implementation of this type are more intricate, thus necessitating other hardware facilities.
- Higher Cost: Since the concept of Harvard architecture calls for two sets of memory and two separate buses, their implementation costs are comparatively high than Von Neumann architecture.
- Less Flexibility Competitors : Changing or even improving the system can also be a little tricky because of the different memory regions.
Difference between Von Neumann and Harvard Architecture
| VON NEUMANN ARCHITECTURE |
HARVARD ARCHITECTURE |
| It is ancient computer architecture based on stored program computer concept. |
It is modern computer architecture based on Harvard Mark I relay based model. |
| Same physical memory address is used for instructions and data. |
Separate physical memory address is used for instructions and data. |
| There is common bus for data and instruction transfer. |
Separate buses are used for transferring data and instruction. |
| Two clock cycles are required to execute single instruction. |
An instruction is executed in a single cycle. |
| It is cheaper in cost. |
It is costly than Von Neumann Architecture. |
| CPU can not access instructions and read/write at the same time. |
CPU can access instructions and read/write at the same time. |
| It is used in personal computers and small computers. |
It is used in micro controllers and signal processing. |
Conclusion
Von Neumann and Harvard architectures have certain advantages and disadvantages, and it is possible to select the one depending on the further application of the device. For general purpose computing Von Neumann architecture is mostly used as it is easier and cheaper to implement while Harvard architecture is used widely, especially when speed is a major factor, as in use of embedded systems.
Difference between Von Neumann and Harvard Architecture-FAQ’s
Which architecture is more prevalent today in modern Computers?
Most contemporary main-stream GPCs employ Von Neumann architecture while a few restricted custom CPCs such as embedded systems may work with Harvard architecture.
Does it make sense to run an information and a control program within a single computer that implements both Von Neumann and Harvard architectures?
Actually, there are a number of contemporary microprocessors that employ a somewhat different Harvard architecture, which incorporates some features of both types of design.
What makes Harvard Architecture to be viewed as more secure?
There are less likely Lookup table modification as the Harvard architecture of Moto restores provides for separate data and instruction memory spaces – with normal data memory not capable of modifying instructions.
What kind of applications can one associate with Harvard architecture?
So Harvard architecture can be implemented for the usage in such type of devices as the embedded systems, for digital signal processing, applications that demands high-speed processing including low latency.