What is PCI?

Short for peripheral component interconnect, PCI was introduced by Intel in 1992. The PCI bus came in both 32-bit (speed of 133 MBps) and 64-bit versions and was used to attach hardware to a computer. Although commonly used in computers from the late 1990s to the early 2000s, PCI has since been replaced with PCI Express.

Revisions came in 1993 to version 2.0, and in 1995 to PCI 2.1, as an expansion to the ISA bus. Unlike ISA and other earlier expansion cards, PCI follows the PnP specification and therefore did not require any jumpers or dip switches.

PCI overview-

The picture below shows an example of what PCI slots look like on a motherboard. As you can see, there are three PCI slots: PCI4, PCI5, and PCI6, and a CNR slot.

Examples of PCI devices

• Modem
• Network card
• Sound card
• Video card

PCI device drivers

If you are looking for PCI drivers, you most likely need to download them for a specific PCI device. For example, if you need a PCI Ethernet adapter driver, install the drivers for the network card. See our drivers overview for a listing of drivers.

How many PCI slots are on a motherboard?

The number of PCI slots depend on the manufacturer and model of the motherboard. Today, very few motherboards come with any PCI with the introduction of PCI-E. Those few motherboards that do come with PCI slots have between one and three PCI slots.

How can I add a PCI card if I don't have a PCI slot?

To connect a PCI card to a computer, the computer's motherboard must have a PCI slot. As mentioned above, some of today's computers no longer come with a PCI expansion slot. If your motherboard does not have a PCI expansion slot, we recommend getting a more modern card that's supported by the motherboard.

What is an 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-

• 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 expansion card slots above are obsolete. You're most likely only going to encounter AGP, PCI, and PCI Express when working with computers today. 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 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.