The motherboard is the heart of every computer, and every motherboard has certain expansion slots on it which are used for connecting additional peripherals to the machine itself. In most cases, the expansion slots are also present at the back or the sides of the machine, which makes it very easy for the user to connect any additional peripherals with ease. These slots are more commonly found in desktops, since the CPU unit has the space to house many such slots. On the other hand, laptops rarely have many slots on their sides, and only house slots which can help the user connect some basic peripherals.
Different models of motherboards will have different types of expansion slots, and will also have them present in different numbers. Knowing about such slots will increase your knowledge about your machine and its basics and this information could prove useful in many different ways. All motherboards come equipped with tools that help in sound production, graphics quality, wired and wireless networking and video production, there are many people who like to attach additional devices and cards that can improve the performance of their machines. This is where expansion slots come in handy, since they give the user the flexibility to attach any expansion card they want, as long as it is compatible of course.
Motherboard Expansion Slot Types
AGP stands for Accelerated Graphics Port, and this slot is commonly used for attaching graphics cards and 3D accelerators to computers. These cards were introduced to the world by Intel, and they make graphics production better because they interact directly with the system memory on the machine. These slots have been popular for many years now, but they have slowly been phased out in favor of PCI Express slots, which offer faster bandwidth and greater compatibility with other kinds of cards as well.
PCI Express Slots
This is the newest version for such slots, and it has overtaken previous versions like AGP and PCI (Peripheral Component Interconnect) slots. There are many different versions of PCIe cards available today, and all of these differ from each other based on the number of lanes that they possess. The most common use of these slots is to attach 3D cards and graphics cards though, since they offer the best graphical output possible. Some machines are still manufactured with PCI slots though, but these will soon be phased out completely.
PCI is the older standard of PCIe slots, and all machines and motherboards were manufactured with these slots ever since their development by Intel in 2003. Their bandwidth transfer rate is much lower though, and this is what made people realize the need for a better nature of slot though, and this is what led to the development of PCIe slots in the first place.
ISA stands for Industry Standard Architecture and this concept was introduced by IBM in 1984. These are very old slots which started the ball rolling in the first place, and they have become obsolete now. The reasons for this are the extremely slow bandwidth speeds and the rather large size of the slots. These slots are almost twice as large as the standard PCI slots that are found in computers today.
VESA stands for Video Electronics Standards Association, and these slots were present at the same time as ISA slots. VESA slots are also obsolete now, and this is primarily because they had very limited compatibility with a large number of expansion cards. The bandwidth speeds were much higher than the ISA slots at the same time, so there were a few people who preferred these slots instead, but the introduction of new standards and new technology quickly changed the scenario for VESA expansion slots.
These slots are present in laptops, and their unique feature is that they can be used even when the laptop is switched on and is running. Hence they are known as 'hot pluggable' and this feature is necessary in laptops since they cannot be opened up every single time an expansion card needs to be attached. Commonly, PC cards and ExpressCards are used in such slots, and this allows laptop users to get the flexibility and the features that desktop owners regularly enjoy.
A few more types of expansion slots which are not widely used today are as follows.
- ACR (Advanced Communications Riser)
- AGR (Advanced Graphics Riser)
- Amiga Zorro II and Zorro III
- AMR (Audio/Modem Riser)
- CNR (Communications and Network Riser)
- EISA (Extended Industry Standard Architecture) Slots
- PDS (Processor Direct Slot)