Types of Computer Expansion Slots


Types of Computer Expansion Slots

Expansion slots are located on the motherboard, and openings on the back of the computer allow the ports on the cards that go in the slots to be accessed.   There are several types of expansion slots, including AGP, PCIe (also known as PCI express), PCI, and ISA.
 
The smaller card simply needs an empty spot in the case to be mounted to.  It does not need to be placed into an expansion slot on the motherboard. Types of Expansion Slots:

        ISA
        AGP
        PCI
        PCIe, which is short for PCI express


ISA Slots
ISA slots are an older type of expansion slot, twice as big as PCI slots and slower than PCI slots as well.  ISA slots are usually black, while PCI slots are usually white.  ISA slots are not used much anymore, but most computers still have at least one of them.ISA networking cards, ISA sound cards, ISA video cards, and other types of ISA expansion cards can be used in the ISA slots.

PCI Slots
The photo above is a picture of a PCI expansion slot, the most common expansion slot. PCI slots can handle 64 bits of data at a time, twice as fast as ISA slots, which can only handle 32 bits of data at a time. PCI is an abbreviation for "Peripheral Component Interconnect." A 64-bit PCI slot has 64 connections to the motherboard, and each connection is capable of handling 1 bit of data at a time. A 32-bit ISA slot has 32 connections to the motherboard, each handling one bit of data at a time.  (Note: Older technology ISA slots are 8-bit and 16-bit. The newer EISA, (or Extended ISA), slots are capable of 32-bit data transfer. Older PCI technology is 32-bit. The newer PCI technology is 64-bit.)
 
As technology changes new expansion cards become available.  These include video cards, which allow a monitor to be connected to the computer, sound cards, which allow speakers and a microphone to be connected to the computer, and networking cards, which allow computers to be linked together.

AGP Slots
The AGP expansion slot connects AGP video cards to the motherboard. The video card shown above is an AGP GeForce FX 5500. Video cards are also known as graphics cards.  They process video and image data that will be displayed on your screen.  The monitor plugs into the video card.  AGP is an abbreviation for Accelerated Graphics Port. Most AGP video cards are capable of a higher data transfer rate than PCI video cards. Video cards, like the one shown above, simply plug into an AGP slot and connect a monitor or other video display device to a computer, usually through the VGA port.  The video card shown above has three different ports, for three different types of monitors. The "DVI Out" connector connects to a “digital video display”. DVI is an abbreviation for Digital Video Interface. Video cards with a TV output connection are capable of displaying a computer's video on a television instead of a computer monitor, which is great for playing movies on your computer.  Unfortunately, most televisions only support a very low resolution and refresh rate when hooked up to computers.  Video cards with a TV input connection are able of displaying a television's video on a computer.  This allows you to record television programs onto your computers hard drive.  The VGA connection is the standard connection to most monitors. 
 
PCI EXPRESS
PCI Express is a new technology that is slowly replacing AGP. PCI Express x16 slots can transfer data at 4GBs per second, which is about twice as fast as an AGP 8x slot!   PCIe stands for PCI Express, or PCIexpress. PCI Express slots come in five different sizes and speeds: PCIe x1, PCIe x2, PCIe x4, PCIe x8, and PCIe x16. PCIe x16 slots are used for graphics cards.