Difference Between Expansion Slots
- Difference Between Pci And Expansion Slots
- The Difference Between Expansion Slot And Bus
- Difference Between Expansion Slots And Expansion Cards
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.
Even though the expansion slots are all standardized, expansion cards come in different lengths. You can find full-length cards, half-size cards, and others. Smaller PC consoles may have room for only smaller expansion cards, or perhaps some expansion slots are limited to hosting only shorter expansion cards. Likewise, you can plug x4 expansion cards into x4, x8, and x16 slots and you can plug x8 expansion cards (if you can find one) into x8 and x16 slots. But you can't 'down-plug' PCI-Express cards because an expansion card with a higher number of lanes (the 'x' value) physically won't fit into an expansion slot with a lower number of lanes.
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
PCMCIA is an acronym for Personal Computer Memory Card InternationalAssociation; the acronym is pronounced as separate letters. PCMCIA isa non-profit trade association and standards body consisting of some500 companies. PCMCIA has developed a standard for small, creditcard-sized devices, called PC cards, that are often used in notebookcomputers. (Adapters are available that allow PC cards to be used indesktop computer systems.) You can visit the PCMCIA web site at:
In the past, the cards were known as PCMCIA cards, but they are nowreferred to as PC cards, PC card hosts, and PC card software.PCMCIA refers to the association and standards body.
A PC card slot is an expansion slot often found in notebook computersthat allows for the easy and quick addition of a host of differentdevices. Originally designed for adding memory to portablecomputer systems, the PC card standard has been updated several timessince its original creation.
PC cards are Plug and Play devices that are often hot-swappable (i.e.,cards may be removed and inserted with the computer power turned on,without rebooting) under Mac OS and Windows 95and beyond. (Windows NT, however, has more limited supportfor PC cards, and you cannot change cards on the fly.) Many systemswill give a familiar beep sound from the computer's speaker when youremove or insert a card.
Difference Between Pci And Expansion Slots
Differences between PC cards
There are three different types of PC cards. All three have the samerectangular size (85.6 by 54 millimeters), but different thicknesses.
- Type I cards can be up to 3.3mm thick, and are used primarily for addingadditional ROM or RAM to a computer.
- Type II cards (the most common) can be up to 5.5mm thick. Thesecards are often used for modem, fax, SCSI, andLAN cards.
- Type III cards can be up to 10.5mm thick, sufficiently large forportable disk drives.
Differences between PC card slots
As with the physical PC cards, PC slots also come in three sizes:
- A type I slot can hold one type I card
- A type II slot can hold one type II card, or two type I cards
- A type III slot can hold one type III card, or a type I and typeII card.
Most notebook computer systems come with two PC card slots that allowfor the use of two type I or type II PC cards and one type III PCcard. The PC card slots are stacked with one above theother. Usually, type III PC cards fit only in the bottom slot.
Common PC card devices
Following is a list of common PC card devices:
- CD-ROM interface
- Cellular phone interface
- Security tokens
- Docking station interface
- 10Mbps Ethernet LAN adapters
- 100Mbps Ethernet adapters
- GPS (Global Positioning System) cards
- Hard drives
- Infrared wireless LAN adapters
- ISDN cards
- Joystick interface cards
- Memory cards
- Modem and Ethernet combination cards
- Parallel port interface
- SCSI adapters
- Serial port interface
- Sound cards, input and output
- Video capture/frame grabber cards
- Video teleconferencing cards
Cardbus
The Difference Between Expansion Slot And Bus
Many laptop manufacturers now advertise their PC card slots as cardbuscompatible, or they simply identify the slots as cardbusslots. Cardbus is an extension of the latest PCMCIA standard, whichexpands the bus bandwidth and throughput to 32bits at 33MHz. In contrast, the older PC card standard was16 bits at 8MHz. Cardbus is analogous to the PCI slots in desktops,while the older PC card standard is analogous to ISA. The newercardbus slot can accommodate an older 16-bit PC card, but an older PCcard slot cannot accept newer cardbus cards. To tell if your PC cardis cardbus, look on the interface end of the card. Cardbus deviceswill have a notched metal plate on that end.
While not technically accurate, some vendors and technicians refer tothe older style 16-bit PC card as PCMCIA in order to contrast it with32-bit cardbus cards, which makes them sound like competingstandards. However, cardbus is an extension to the PCMCIA standard,not a replacement.
For additional information, see:
ExpressCard
The latest extension of the PCMCIA standard is calledExpressCard. This standard is being built on the latest USB2.0 and PCI Express buses. The aim is to increase speed and reducesize, cost, and complexity. One of the ways it does this is toeliminate the PCMCIA Host Controller in favor of using the USB or PCIExpress controller directly.
Difference Between Expansion Slots And Expansion Cards
For additional information, see: