Thursday, April 16, 2009

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.

The picture below shows the SoundBlaster Live sound card, with additional ports attached to it through an IDE cable. There are several types of expansion slots, including AGP, PCIe (also known as PCIexpress), PCI, and ISA.




The top card of the SoundBlaster Live sound card plugs into a PCI expansion slot, while the bottom card sends and receives its data to and from the larger card through an IDE cable. 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 PCIexpress

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.)

The diagram below shows how to properly insert a PCI card into an empty PCI expansion slot.







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. There are also many other types of expansion cards. Below is a photograph of a Promise PCI expansion card. It allows you to connect up to four additional drives to your computer with IDE cables. This expansion card provides data transfer rates of up to 66,000,000 bits per second, (or 66Mbs/sec). This technology is also known as Ultra ATA/66. ATA is an abbreviation for "Advanced Technology Attachment." Ultra ATA/66 is also known as Ultra DMA/66. DMA is an abbreviation for "Direct Memory Access." Ultra DMA/66 devices can directly access the RAM, transferring 66 million bits of data per second.



Below is a picture of Creative Lab’s Sound Blaster Live Value PCI sound card. A sound card is what processes sound and allows speakers and a microphone to be hooked up to the computer. When you hear music coming from your computer's speakers, the sound card's digital signal processor, also known as the DSP, is working together with the digital-to-analog converter, also known as the DAC, processing and converting digital sound data (electrical pulses represented by binary code) to analog sound data (increases and decreases in electrical pulses that the speaker interprets and generates as increases and decreases in tone, frequency, and volume.) When you talk into your computer's microphone, the sound card's digital signal processor works along with the analog-to-digital converter to process and convert analog sound data to digital sound data, which can be saved onto your computers memory. Record players are analog – they are made of tiny engravings that the needle moves through, that move back and forth in a wave shape to change the frequency of the sound. Computers, however, are digital. A music file stored on a computer hard drive is stored as a series of positive and negatively (north and south) magnetically charged sectors on the hard drive. These are represented by 1s and 0s in what is called binary code. Different sequences of these magnetic charges instruct the computer to perform different tasks, and in this case, tell the computer what frequencies and volumes to play when playing the music file.

Better sound cards have better sound, however, you can save a ton of money by just buying a mediocre sound card online (I recommend
www.newegg.com for those interested in buying computer parts – there’s even better deals on neweggs older website, just click on “Newegg Old Version” or something like that at the top right hand corner of the homepage of newegg.com) The Sound Blaster Live Value card allows you to connect a sound input device, like a CD-Player or radio, a microphone, front speakers, rear speakers, and a joystick or MIDI instrument, like an MIDI keyboard. The front and rear speakers can be combined together to produce stereo surround sound. Just like the video card, the sound card uses its own little processor to process sound data.
Below is a picture of a SCSI (pronounced “sscuhzy”) PCI expansion card. SCSI is an abbreviation for "Small Computer Interface System." With a SCSI expansion card, you can connect up to fifteen devices to one SCSI connection. SCSI is one of the fastest data transfer interfaces there is. SCSI cards are available with transfer rates up to 320 MB per second! The Ultra320 SCSI-3 interface is the fastest SCSI interface, with a 320MB/sec data transfer rate! Below is a picture of a PCI SCSI expansion card.

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.

The quality of the display depends mostly on the type of video card, but also on the type of monitor. There are many factors in determining how good a video card is, but the most important, in my opinion, is video-RAM. Video cards have their own RAM, called “video-RAM” and the more RAM the video card has the faster the video card, and your computer, will run. Go to “Display Properties” from the control panel or by right clicking on your desktop and clicking “Properties” and then click “Settings” and click “Adapter” to see how much video RAM your current video card has. If you have less then 128 megabytes of Video-RAM in your desktop, and you play a lot of computer games, I would highly recommend upgrading to a video card with 128 megabytes of video-RAM, such as the NVIDIA GeForce MX400 128Mb PCI, which goes in the PCI expansion slot. I bought it for only fifty dollars online (it’s normally a hundred dollars in stores but I got a great deal on it from
www.newegg.com I recommend www.newegg.com for those interested in buying computer parts – there’s even better deals on neweggs older website, just click on “Newegg Old Version” or something like that at the top right hand corner of the homepage of newegg.com). After upgrading from a measly eight megabyte video card to the NVIDIA GeForce MX4000 128MB PCI video card, my computer performed twice as fast! Games that used to take up to fifteen minutes to load would load in seconds!
Anyway, let’s get back to talking about AGP cards. The photograph below shows what an AGP expansion slot looks like.
AGP slots and cards come in four different modes, and you must be careful to match the card and slot with the correct mode. Some AGP cards and AGP slots are capable of running in more than one mode. AGP 1x mode is the oldest; it transfers data at 266MBs per second. AGP 2x mode transfers data at 533megabytes per second. AGP 4x mode transfers data at 1.07 gigabytes (1007 megabytes) per second. The latest AGP mode is AGP 8x. It transfers data at 2.14gigabytes (2140 megabytes) per second!

Below is a picture of three PCI Express slots.

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.

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