Pc expansion bus: Why does a computer need an expansion bus? As a tech expert myself, I have faced this question many times, and no matter how many times I have explained to people its functionalities, they somehow end up forgetting the lesson. That’s why I thought it is better to simplify the whole thing once and for all to help beginners understand the importance of expansion buses.
This article will take you on a step-by-step journey to clarify your ambiguity surrounding an expansion bus. First, we will explain what an expansion bus is, its types, functions, and why a computer needs it. So, without further ado, let’s get started.
Table of Contents
What Is An Expansion Bus?
An expansion bus is a set of cables that enables the computer to expand through an extension board. The extension board is a printed circuit board fitted into an expansion slot on the motherboard and adds new functionality to the system.
An expansion bus is a data transmission route between core hardware like the CPU and the RAM and expansion devices like a sound card or graphics card.
The system bus and the expansion bus are the two subcategories of the external data bus. The CPU, RAM, and other motherboard components are all supported by the system bus. The system bus takes at the very same speed as the CPU. The extension bus operates at a constant 7.16 MHz and accommodates any add-on devices through expansion slots.
The total efficiency of the system is improved by dividing the expansion bus. That’s because the CPU operates on the system clock, and replacing a CPU simply necessitates altering the system bus timing while existing expansion cards continue to function normally. Changing the system clock frequency to match the CPU is generally done via a jumper adjustment. Unfortunately, the CPU speed is limited by the motherboard’s capacity to make this adjustment. Following that, we’ll take a look at the many sorts of expansion buses that have evolved throughout time.
Types Of Expansion Bus
There are different types of expansion buses such as;
- ISA (Industry Standard Architecture)
- PCI (Peripheral Component Interconnect)
- AGP (Accelerated Graphics Port)
- PCI-X (PCI Express)
The ISA, which was used with IBM-compatible computers, is among the first forms of extension buses. It may be used with a network card, a video card, or more serial ports. On the other hand, the ISA bus was prone to delays and was eventually superseded by the PCI bus. The PCI has quicker specifications with a bus speed of 33 or 66 MHz and support for 32- and 64-bit data channels. The PCI Express bus, which has taken the place of the PCI, is even quicker.
The PCI interface is utilized in many existing computer interfaces and adheres to the Intel Corporation’s local bus specification. Even though the PCI Express interface is quicker, the PCI is more widespread and may even be installed on some Macintosh systems. Some PC designs, such as the NuBus and Macintosh, employed their native buses before the PCI interface.
What Functions Do The Expansion Bus Perform
The functions of an Expansion Bus are;
- Expansion bus ports are lengthy, narrow connections on the motherboard towards the computer’s rear being used to interconnect all of the system’s add-on cards.
- They offer a direct electromagnetic link to the logic circuits of the PC. As a result, it lets users enter expansion boards to their computer systems, which are critical in increasing a PC’s capacity and functionality.
- Expansion bus controls what may be installed in the PC, such as the number of add-on cards, the memory space on expansion slots, other system components, and how simple it is to set up the whole system.
- It connects the many subsystems of the PC by providing a common channel for information, address, and control signals.
- Expansion bus must also ensure that data reaches its intended destination, i.e., the computer transfers specific patterns of digital data in a particular sequence from one location to another via bus circuits.
- The expansion bus sends out specific signals to synchronize add-on cards and the rest of the system.
Why Does A Computer Need An Expansion Bus?
Expansion buses on a motherboard bridge are standardized connectors that allow any device that isn’t connected to the motherboard to be installed. Computers may be modified to fit the user’s needs by giving this link to the expansion bus. In addition, a variety of virtual peripheral devices are integrated into the motherboard of modern PCs.
As a result, expansion slots may be empty, but that does not imply that expansion buses in that system remain vacant. All built-in peripherals and connectors still interact with the CPU via the I/O bus, which means they function as if they were add-on cards placed into the system’s expansion bus slots.
Since the original PC, various extension bus types have developed on the PC platform, all intending to improve system performance by offering higher I/O speeds. The demand for improved performance emerges primarily as a result of advancements in some key areas:
- Processors that became more efficient
- Increasing software needs for applications
- Multimedia audio and visual requirements are becoming more urgent.
- Peripherals became much faster.
Therefore, these are some of the main reasons a computer needs an expansion bus.
Putting It All Together
We have elaborated a clear definition of expansion bus in this article. We have also elaborated on its types, functions, and role in enhancing the performance of a computer. So, if you have reached the end of this article, you probably have grasped a good idea of why a computer needs an expansion bus. We suggest you give this article a thorough reading one more time to learn the concept entirely.