Different Types Of Expansion Slots
Different Types Of Expansion Slots

The three most common expansion interfaces in current use are: At the time of this writing, the PCI Express slot is the most popular kind of expansion slot. It can be used for literally any kind of expansion card. At the time of this revision, there are four sizes of PCI-e slots called x1, x4, x8, and x16.
When purchasing a new Server, Workstation or PC to support an expansion card one of the most important things to determine is what type of slot does the motherboard have. There are 3 types of slots that have been used for over the years: ISA, PCI, and PCI Express (PCIe).
That means that—potentially—any storage or disk drive, GPU or port expansion, or low-power gadget that uses a USB connection, could all be mounted on a card plugged into the M.2 slot at the same time. The reality is a little more complicated—for example, a single M.2 slot only has four PCI Express lanes, a quarter of the total generally.

Which type of motherboard expansion slot has four types ranging from x1 to x16 with each type having a different length of expansion slot?

Alternatively known as a bus slot or expansion port, an expansion slot is a connection or port inside a computer on the motherboard or riser card. It provides an installation point for a hardware expansion card to be connected. For example, if you wanted to install a new video card in the computer, you'd purchase a video expansion card and install that card into the compatible expansion slot.

Computer expansion slots

Below is a listing of expansion slots commonly found in a computer and the devices associated with those slots. Clicking on any of the links below provide you with additional details.

AGP - Video card.
AMR - Modem, sound card.
CNR - Modem, network card, sound card.
EISA - SCSI, network card, video card.
ISA - Network card, sound card, video card.
PCI - Network card, SCSI, sound card, video card.
PCI Express - Video card, modem, sound card, network card.
VESA - Video card.

Many of the above expansion card slots are obsolete. You're most likely only going to encounter AGP, PCI, and PCI Express when working with computers today. In the picture below is an example of what expansion slots may look like on a motherboard. In this picture, there are three different types of expansion slots: PCI Express, PCI, and AGP.

How many expansion slots does my computer have?

Every computer motherboard is different, to determine how many expansion slots are on your computer motherboard identify the manufacturer and model of the motherboard. Once you've identified the model of motherboard, you can find complete information about the motherboard in its manual.

Adding additional expansion slots for older motherboards could be accomplished by using a riser board, which would add several ISA or PCI slots. Today, riser boards are rarely used with motherboards, as there is limited need for additional expansion slots with modern motherboards.

What type of expansion slots are on my motherboard?

As mentioned above, every motherboard model is unique, so to determine the type of expansion slots on the motherboard, consult the board's specifications and owner's manual. You can also open the computer case and visually examine the motherboard.

Why do computers have expansion slots?

Computers have expansion slots to give the user the ability to add new devices to their computer. For example, a computer gamer may upgrade their video card to get better performance in their games. An expansion slot allows them to remove the old video card and add a new video card without replacing the motherboard.

What is the most common expansion slot today?

Today, the most commonly used expansion slot used and found on computer motherboards is the PCI Express expansion slot.

Does a laptop have an expansion slot?

Laptops do not have expansion slots like a desktop computer. However, some laptops do have PC Cards that can be inserted into the side of the laptop. They may also have a Cardbus slot for an ExpressCard to be added.

Related expansion slot pages

Expansion, Expansion card, Motherboard terms, Seated

PC Card Slot Types

ISA
AGP
PCI
PCI-X
PCI-E (PCIexpress)

ISA

ISA, or Industry Standard Architecture, is an 8bit or 16bit parallel bus system that allowed up to 6 devices to be connected to a PC. Virtually all IBM-compatible PCs made before the Pentium were based on the ISA (IBM's PC AT) bus. This asynchronous bus architecture uses 16-bit addresses and an 8-MHz clock and handles a maximum data throughput of 2 MB/s to 3 MB/s.

ISA is the precursor to PCI. Standing for 'Industry Standard Architecture' It was common from the early 1980s to the mid 1990s. ISA was a typically inelegant solution for the time, and required one to know exactly what one was doing- PnP was rare, even for so called 'ISA PnP' peripherals. In the end, the combination of flexibility, ease of use, and greater capability allowed PCI to supersede ISA.

PCI

The PCI bus architecture is a processor-independent bus specification that allows peripherals to access system memory directly without using the CPU. Not only does this free up the CPU to service other application calls, but PCI users also can simultaneously acquire data to memory and analyze existing data in real time, all while communicating with other functions on the network.

More importantly, PCI peripherals running asynchronously can send data along the 32-bit bus at a rate of up to 132 MB/s or 66 MS/s.

AGP

The Accelerates Graphics Port is a high-speed point-to-point channel for attaching a video card to a computer's motherboard. It was created in 1997 yet by 2004 was largely replaced by PCI Express. The primary advantage of AGP over PCI is that it provides a dedicated pathway between the slot and the processor rather than sharing the PCI bus. In addition to a lack of contention for the bus, the point-to-point connection allows for higher clock speeds. AGP also uses sideband addressing, meaning that the address and data buses are separated so the entire packet does not need to be read to get addressing information. This is done by adding eight extra 8-bit buses which allow the graphics controller to issue new AGP requests and commands at the same time with other AGP data flowing via the main 32 address/data (AD) lines. This results in improved overall AGP data throughput.

PCI-X

PCI-X stands for 'PCI-eXtended'. PCI-X is a computer bus and expansion card standard that enhances the 32-bit PCI Local Bus for higher bandwidth demanded by servers. It is a double-wide version of PCI, running at up to four times the clock speed, but is otherwise similar in electrical implementation and uses the same protocol.[1] It has itself been replaced in modern designs by the similar-sounding PCI Express, which features a very different logical design, most notably being a 'narrow but fast' serial connection instead of a 'wide but slow' parallel connection.

PCI-X revised the conventional PCI standard by doubling the maximum clock speed (from 66 MHz to 133 MHz)[1] and hence the amount of data exchanged between the computer processor and peripherals. Conventional PCI supports up to 64 bits at 66 MHz (though anything above 32 bits at 33 MHz is only seen in high-end systems) and additional bus standards move 32 bits at 66 MHz or 64 bits at 33 MHz. The theoretical maximum amount of data exchanged between the processor and peripherals with PCI-X is 1.06 GB/s, compared to 133 MB/s with standard PCI. PCI-X also improves the fault tolerance of PCI allowing, for example, faulty cards to be reinitialized or taken offline.

PCI Express

PCIe, or Peripheral Component Interconnect Express, is a computer expansion card standard designed to replace the older PCI, PCI-X, and AGP standards. PCI Express i

Different Kinds Of Expansion Slots