Computer Terms

Glossary of Computer Terms

3D:
Everybody knows what 3D is, but what is it in a computer? 3D is generally
what is used to refer to the capabilities of the video card. Today's video cards use
a variety of instructions built into the video card itself (not software) to achieve
more realistic graphics in computer games that appear to have depth. Most of
today's video cards have these capabilities, but there are incredibly large
differences between specific cards. That's why you need to read the Video Card
recommendations. These 3D capabilities are generally used for games, but
high-end video cards are used for creating 3D models and 3D animation. Many
of these cards cost well over $1,000 and are not intended for home use.

3D Audio: Again, this is for gaming more than anything else. Sound cards such
as the Live! and Diamond MX300 use techniques that I do not fully understand to
make your speakers present sound that sounds like it is coming from behind or
beside you instead of in front of you where your speakers are. The true effect is
best with a set of four speakers.

3DNow!: AMD's set of additional instructions that they integrated into their
CPUs. Similar to MMX and SSE/KNI, these instructions are intended to speed
up CPU performance. These only appear in AMD CPUs.

AGP: Accelerated Graphics Port is a high-speed connection only used by video
cards, so there is only one of them in a computer (older computers do not have
AGP). It is faster than PCI and has direct access to system memory so that the
computer's memory can be used in addition to the video card's memory. Default
AGP speed is 66 MHz.

AMR: Audio Modem Riser and CNR (Communications Network Riser) are slots
on motherboards that can accommodate low cost sound cards, network cards,
etc. So far there isn't really much available for these slots, and they're not likely
to be used much in the future either.

ATA: See IDE.

AT/ATX: These are two standard types of motherboards, cases, and power
supplies. An ATX motherboard generally must be used in an ATX case with an
ATX power supply. When upgrading your computer, you need to know what type
you have and what type you will be getting. If they're not compatible they won't
work. ATX is becoming the norm, particularly for Pentium II, III, and Celeron
computers. Retail computers like Gateway, Dell, Packard Bell, and Compaq
often have their own proprietary standards. These often cause problems and
prevent users from upgrading their motherboards and other components.

BIOS: This is the Basic Input/Output System and is installed on the computer's
motherboard. It controls the most basic operations and is responsible for starting
your computer up and initializing the hardware. It is data that is usually held in a
ROM chip, which can be updated by "flashing". BIOS upgrades may correct
errors, support new CPUs, support new hardware, etc.

Burner (CD-ROM): This is a device that allows you to save data to a CD-ROM.
Special CD-Rs are required for this. They also allow you to make backup copies
of your CDs. There are a large variety of types, including CD-R or CD-R+RW.
The latter has support for rewritable CDs which can be erased and rewritten to,
while CD-R only drives can only write to their CDs once. Like CD-ROM drives,
burners can be IDE or SCSI. SCSI is definitely preferable when it comes to
burners, but a SCSI card is required. Burners are generally quite picky and must
have a constant stream of data to work properly. If that stream is interrupted, the
burn will fail. This is one reason why SCSI burners tend to be better; SCSI
devices can deliver a more reliable stream of data than IDE, while other
applications are being run as well.

Bus or System Bus: This is just a collection of wires that transmit data from one
component to another.

Bus Speed: This is a speed measured in Megahertz that determines how fast the
memory and CPU run. The only "official" bus speeds supported by Intel are 66
and 100. However, numerous others exist (75, 83, 103, 112, 124, 133, 153,
etc.). High-quality memory is required for the higher bus speeds. The bus speeds
usually determine the speed of the PCI and AGP buses as well The default PCI
bus speed is 33 and the default AGP bus speed is 66 MHz.
The CPU speed is determined by a combination of the bus speed and multiplier
(i.e. 100 bus speed x 4.5 multiplier = 450 MHz CPU speed).

Cache: It's said just like cash, but has an entirely different meaning. Cache
memory is the fastest type of RAM available and is used in CPUs, hard drives,
and a variety of other components. As with RAM, the more cache, the better, but
CPU and hard drive cache generally cannot be upgraded. Pentium II CPUs have
512 Kilobytes of cache, and the high-end IBM 9LZX SCSI hard drives have a
large 4 Megabytes cache. Like RAM, data generally passes through cache
memory before going to the component that is going to use it (the CPU). It holds
the data for quick access as well. The speed of the cache is also very important.
Pentium II CPUs have 512 k cache, and Celeron CPUs have 128 k of cache, but
the Celeron cache runs at full CPU speed while the Pentium II's cache runs at
1/2 CPU speed. Thus, there is a tradeoff that makes the Celeron run about as
fast as the Pentium II CPU.

Case: The computer's case is nothing more than its shell or a skeleton. The
case performs the function of holding the computer together, cooling (with fans),
and grounding the computer components through its steel. Larger cases with a
lot of expansion bays are preferable. This way you can have a lot of room to work
in your case and be able to upgrade with more hard drives, DVD drives, burners,
etc. Super Micro’s SC750-A server tower is an example of a great case. It has a
total of 8 external bays, plenty of room to work, and a great cooling setup with
space for a lot of fans. Tower cases are generally preferred over desktop cases
because they have more room for expansion and better cooling capabilities. A
case can be AT or ATX, differing in the way the holes are laid out to connect the
motherboard to and the type of power supply if it comes with one. Cases
generally come with power supplies, but it is often advisable to get them
separately so that you can get high quality parts for both.

CD-ROM Burner: See Burner.

CD-ROM Drive: Reads compact disks in the form of audio or CD-ROM. A CDROM
holds data (perhaps audio as well). Newer CD-ROM drives will read CD-R
(Writable CDs) and CD-RW (ReWritable CDs). The speed of a CD-ROM drive is
not usually very important except when installing programs, running games that
require use of the CD-ROM drive, or "burning" CDs with a CD-ROM Burner - a
CD-ROM drive that is able to write to special CDs called CD-Rs. Visit the CDROM
Drive page.

CNR: See AMR.

Chips/Chipsets: These are the little pieces of silicon that hold computer
information and instructions. Just about any computer component has at least
one chipset on it. Motherboard chipsets control the basic ins/and outs of the
computer. Video card chipsets control the rendering of 3D graphics and the
output of images to your monitor. The CPU is just a very important chip.
Common motherboard chipsets include the BX, i810, i820, and many others.

Color Depth: Refers to the number of colors displayed to the monitor by the video
card. The more colors used, the more realistic the display. With photographs,
changing the computer's color depth may or may not help if the picture is limited
to a small amount of colors. Common color depths are 256 colors, 16-bit (65,000
colors), 24-bit, and 32-bit (millions of colors). 24-bit and 32-bit are difficult to
differentiate between, but 16-bit and particularly 256 colors will show a noticeable
lack of quality or realism.

CPU: The CPU is the computer's control center. Think of it as the brain that does
all the thinking (computation), thus it is called the Central Processing Unit. The
actual CPU is about 1.5 inches square, yet it is the most critical part of the
computer. Having a fast CPU (measured in Megahertz) greatly aids in the
overall speed of your computer. Visit my CPU Page.

DDR: This is a new type of RAM called Double Data Rate RAM. It is used in
some of the newer video cards such as the Nvidia GeForce cards.

Digital Camera: This is a camera that does not use film, but instead stored the
photographs in a digital format in memory on the camera. These images can
then be downloaded to a computer.

DIMM: This is a type of memory connection that uses 168 pins. The most
common type of DIMM is SDRAM (see it for more information). DIMM stands for
Dual Inline Memory Module. DIMMs are the successor to SIMMs (Single...). The
most common type of SIMM is EDO and is used primarily in older Pentium
computers.

DPI: Dots per Inch is a measurement used both on monitors and printers. The
measurements are done different ways though. The higher numbers on printers
generally represent more detailed print quality (i.e. 1440x1440 would be very
high resolution printing). The lower numbers on monitors represent clearer
picture quality (i.e. .22 dpi would be a very high quality monitor).

DVD-ROM Drive: Similar to a CD-ROM drive, a DVD Drive reads CDs, CDROMs,
and the newer DVDs. The acronym DVD originally had no meaning, but
has since been referred to as Digital Video Disk and Digital Versatile Disk.
DVD's advantage over CDs is that it holds many times the capacity of a single
CD. DVDs can also hold full-length movies and can be used double-sided for
extra storage. Currently very few software titles are available only on DVD-ROM,
but are also available on CD-ROM, usually requiring multiple CDs. DVD videos
are only available on DVD though. DVD also requires and MPEG decoder card
to view the Videos. Software DVD decoding can be done on very fast machines,
but hardware decoding (simply meaning a piece of hardware is added to the
computer along with the drive - a decoder card) will work much better. Some
more discussion of this appears on the CD-ROM Drive Page.

Ethernet: See NIC.

GigaBytes: This is equal to 1,000 MegaBytes.

Hard Drive: The hard drive stores all the computer's information and retains the
information when the computer is turned off. A fast hard drive is needed to supply
the CPU with data as fast as it needs it. Hard drive sizes are typically measured
in GigaBytes. The larger the number, the more applications and games you can
have installed. A hard drive can be IDE or SCSI. See IDE or SCSI for more
information.

IDE: IDE stands for Integrated/Intelligent Drive Electronics. It is an ATA
specification (the terms are often used interchangeably). This is the most
common disk interface for hard drives, CD-ROM drives, etc. It is easy to use, but
also the most limited. IDE is integrated into your motherboard. It only allows for 4
devices. The other option is SCSI, which is faster, more complicated, and allows
for many more devices. SCSI requires a separate add-on card and different
types of hard drives (SCSI).

ISA: ISA is an older technology for connecting computer peripherals (stands for
Industry Standard Architecture). Common current devices include modems and
sound cards. ISA is much slower than PCI, so PCI devices are generally better if
you have a choice. ISA is starting to fade and eventually will be removed
entirely. Most motherboards still come with at least one or two ISA slots on
them.

KNI: See SSE.

LAN: See NIC.

MegaBytes: Megabytes are the measurement used for the amount of hard drive
space available, used, required, etc. One megabyte is equal to one million bytes
or one thousand kilobytes. One megabyte is small by today's typical file sizes.
Hard drive sizes are commonly given in gigabytes, each of which is one
thousand megabytes. Memory is also measured in megabytes.

Memory: See RAM.

MMX: A set of additional instruction (Multi-Media Extensions) integrated into
CPUs starting with the Pentium MMX CPUs. They are still present in the Pentium
III CPUs, and AMD integrated them into their K6 series of CPUs. The MMX
instruction sets had a fairly small impact. SSE or KNI are a similar set that was
integrated into the Pentium III and later CPUs.

Modem: It stands for Modulator Demodulator, but its use is much simpler. It
enables a computer to "dial-up" to another computer for a variety of purposes
including Fax, Gaming, or Internet connections. There is a large variety of
modems available now including the original 14.4, 28.8, 33.6, and 56k modems
as well as newer ISDN (128k) and ADSL (256k) modems. To use any modem,
your Internet Service Provider must support the format (modem, ISDN, or
ADSL). Also, new phone lines are needed for ISDN, and ADSL must have
support in your area. Visit the Modem Page for more information and
recommendations.

Monitor: The high-resolution TV-like tube that displays your computer's output.
Today's monitors have much better quality displays than any TV is capable of.

Motherboard: The motherboard is easily compared to the human body's nervous
system. The wires (nerves) on it transfer data between all of the other
components. Having a high-quality motherboard (not described in retail
computers) is essential to a reliable computer.

MHz: This stands for the "Megahertz" rating and is the primary measure of a
CPU's speed. One Megahertz is one million clock cycles per second. Thus, a
400 MHz processor will have twice as many clock cycles per second as a 200
MHz processor, but this doesn't necessarily mean it is twice as FAST...

Multiplier: This number works with the bus speed to determine how fast the CPU
is run. A multiplier of 4.5 coupled with a bus speed of 100 MHz yields a CPU
speed of 450 MHz (4.5x100). Most of Intel's newest CPUs are multiplier locked
in that only a specific multiplier can be used and not others (i.e. a 450 MHz CPU
can only use a 4.5 multiplier, but not 4 or 5). The bus speed is independent and
can be changed so that 4.5x100 and 4.5x103 will give different CPU speeds
(provided the CPU will run at that speed).

Networking: See NIC.

NIC: A Network Interface Card allows your computer to connect to a network of
computers. The most common type of NIC is Ethernet - a very fast method of
transferring data between computers. A modem is generally used to dial-up from
a home computer to connect to a network or the Internet. However, an Ethernet
NIC uses a cable that usually connects to a hub, which connects to a router,
which connects to a switch, and these pieces are also often connected to a
server through the same type of cable and to the Internet backbone via a fiber
optic cable. The NIC allows the computer to share with and get resources from
other computers on the network (as well as the Internet if it is not a Local Area
Network (LAN). A LAN is a closed network consisting of 2 or more computers
that are connected through NICs and hubs, generally not connected to the
outside world - the Internet. Hubs allow several computers to share one cable
connection (1 cable connects to another hub or router, and the hub provides 5
(more or less) connections for other computers or hubs to connect to).

Over Clocking: This is the term for running a CPU, video card, or other
component faster than its rated speed.

PC100/PC133: A rating that certifies that the memory is capable of running at
100 or 133 MHz bus. This memory is generally required for running at those
specific speeds.

PCI: "Peripheral Component Interconnect" is a high-speed connection for
devices including SCSI cards; video cards, sound cards, modems, and video
capture cards, etc. This is the primary way of adding devices to your computer.
It is faster than ISA, so is preferred for devices such as sound cards and SCSI
cards. It is slower than AGP, which is for graphics cards only, so AGP graphics
cards tend to be better than PCI ones. Default PCI speed is 33 MHz.

Power Supply: Generally this comes with the case. It can have an AT or ATX
power connector and it is measured in its rated output. It converts power from
your outlets into a steady stream of power the computer can use. A 235 or 250-
Watt power supply is generally sufficient for home users, but power users may
need a 300 or 400 Watt power supply if they have a lot of hard drives or other
components. The quality of power supply can be very important and may make
the difference between a stable computer and a computer that crashes often. I
recommend power supplies from PC Power and Cooling and CalPC.

PPGA: This stands for Plastic Pin Grid Array. PPGA is the same as Socket 370
and is a relatively new CPU connection type. The CPUs are very similar to the
Socket 7 CPUs, but they cannot be used in the same motherboards. Like the
Socket 7 CPUs, they have pins at the bottom of a flat square CPU, and sit
parallel to the surface of the motherboard.

Printer: A printer outputs data that is seen on the computer screen. Most printers
are used through a parallel port, but some newer ones use USB connections.
USB is somewhat faster, but there's not much of a difference for printers.
Networked computers usually print to a printer through the network card. The
most crucial printer measurement is its dots per inch rating. Although this can be
misleading, a higher number is generally better. Printers are best chosen by
actually seeing the quality of the printer output.

RAM (Memory): This is the component that holds recently accessed data for the
CPU to have quick access to. It is much faster than reading from a hard drive, so
having a lot of RAM makes it quick to retrieve recently accessed files,
applications, and other data. All programs must be run through RAM before they
can be used. RAM stands for Random Access Memory and is typically
measured in megabytes.

RDRAM: This is the Intel-backed form of memory that is competing with PC133
SDRAM. It boasts speeds up to 800 MHz for very high bandwidth, but whether or
not it will be worth its high price is a tough call. RDRAM comes in RIMMs, which
will not fit in the BX motherboard DIMM slots.

Refresh Rate: This is the speed at which the monitor's picture is redrawn or
flashed in front of your eyes. Slower refresh rates provide a noticeable flicker.
Higher refresh rates create a steady picture (and is easier on your eyes). The
refresh rate is determined by the video card, but also must be supported by the
monitor. The maximum refresh rate will be different for different resolutions. A
minimum of 75 Hertz is recommended (TV refresh rates are 30 Hz, which is why
there is a noticeable flicker).

Resolution: Similar to dpi, the resolution is how many pixels can be displayed on
the screen at once. The resolution is measured in the number of pixels wide and
high that the display is. The most common resolutions are 640x480, 800x600,
1024x768, 1280x1024, and 1600x1200. Higher resolutions provide sharper,
better quality pictures, but also make type and images smaller since more
information is squeezed onto the same size screen. The size of the monitor is
important when considering the resolution. A 14" or 15" monitor is best with an
800x600 resolution. 1024x768 is best for 17" monitors. 19" monitors can use
1280x1024 or 1024x768 well. 1600x1200 or greater is recommended only for 21"
or larger monitors. The resolution of a TV screen is 640x480; another reason why
a computer's display is much better than a TV's.

RIMM: A RIMM is a form of memory connection much like a SIMM or DIMM.
RIMMs are physically different from the others and cannot be used on a BX
chipset motherboard. RIMM stands for Rambus Inline Memory Module. RDRAM
comes in RIMMs.

Scanner: This device allows you to read images and text into your computer.
Scanners use a variety of connection formats including Parallel Port, USB, and
SCSI. USB is simple, SCSI is fast, and Parallel Port is extremely slow.

SDRAM: This is the most common type of memory used today and is a type of
DIMM. SDRAM (like all memory) is measured by its access time, CAS latency, its
rating, and other timings. Recent ratings are PC100 and PC133, and this
memory is required for newer Pentium II and III CPUs.

SECC: A Single Edge Contact Cartridge is a type of connection for the CPU to
plug into the motherboard. It is the same as Slot 1. All Pentium II and III CPUs
are Slot 1, as are some Celeron CPUs. These CPUs require a Slot 1
motherboard using the BX or LX (older) chipsets as well as newer ones. They
plug into the motherboard much like a PCI sound card or other component
would. Thus, they sit perpendicular to the surface of the motherboard.

SIMM: See DIMM.

Slot 1: See SECC.

Slotket / Sloket: These terms are used to refer to an adapter card that allows a
PPGA CPU (Celeron) to be used on a Slot 1 motherboard. Newer ones also
allow for voltage adjustment.

Socket 370: See PPGA.

Socket 7: This is an older CPU connection format that was used by the Pentium,
Pentium MMX, all the AMD K6 and later CPUs, and several Cyrix CPUs. Slot 1
CPUs cannot be used on these motherboards, nor can Socket 370 CPUs. These
CPUs are flat squares that sit parallel to the motherboard. Their pins plug into the
motherboard.

SCSI: This acronym is pronounced "skuzzy" and stands for Small Computer
Systems Interface. There are two types of interfaces for hard drives, CD-ROM
drives, etc. One is SCSI, the other is IDE. IDE is much more common and less
expensive. SCSI is more expensive and also more flexible and generally faster.
With a single SCSI card you can have 15 or more devices whereas you are only
allowed to have 4 devices with an IDE system. The fastest hard drives (and
generally CD-ROM drives too) are SCSI-based. Examples are the 10,000-rpm
IBM 9LZX hard drive. The fastest IDE drives run at 7,200 rpm. To have a SCSIbased
computer, you have to have a SCSI card, SCSI hard drive, etc. SCSI is
more complicated to configure and should not be taken on by amateurs. There is
a variety of connections such as 25, 50, 68, 68 LVD, 80 SCA, etc. (where the
numbers represent the types of connections.

SSE (KNI): Streaming SIMD Extensions (formerly known as Katmai New
Instructions) represent a set of instructions integrated into Intel's Pentium III
CPUs. Similar to MMX and 3DNow!, they are intended to speed up CPU
performance. While MMX did not have much of an impact, SSE appears to offer
significant improvements. SSE is the primary difference between the Pentium II
and Pentium III CPUs.

Tweaking: This is a term used to describe changing settings, adding programs,
etc. in order to make your computer run faster or more efficiently.

UltraDMA/UltraATA: Also known as ATA/33, this is a technology in newer IDE
hard drives that allows for greater overall throughput. ATA/66 is now available
with many hard drives, which is even faster. However, a 7200-rpm ATA/33 drive
will generally be faster than a 5400 rpm ATA/66 drive. That is, the speed of the
drive itself is much more important than the ATA/33 or 66 rating.

USB: USB stands for Universal Serial Bus and is a new technology theoretically
capable of connecting a very large number of external devices on a computer.
USB is intended primarily for low bandwidth (slow) components such as mice,
keyboards, modems, joysticks, etc., but not fast devices like hard drives. USB
has its benefits and its problems, which I will not go into depth about. Most
computers have 2 USB ports. Some USB devices will have another port so that
another USB device can be plugged into it. This is called "Daisy-Chaining".
Otherwise you run out of ports quickly, in which case you may need a USB hub,
which will add more ports upto 127 (usually 4).

UPS: This stands for Uninterruptible Power Supply, and it is a device that
provides continuous, reliable power to your computer. It is a device that plugs
into your outlets and you then plug your computer, monitor, and other
components into. It uses a battery to make sure that the computer will stay on
even if there is a power outage. These are generally used only for critical
machines and servers, but they can also be useful at home if you have
blackouts/brownouts or voltage irregularities. UPSs made by APS or Opti-UPS is
generally good quality.

Video Capture / Output: This is generally achieved with a video capture card that
is capable of taking video in from a TV or VCR and recording it to a computer
video file. Usually a separate device is required, but some of today's video cards
have this capability built in. If you want to be able to do this, be aware that your
video card must support it, or you must have a video capture card. Computer
generated videos can also be output to VCR tapes.

Video Card: This component is used to transfer data to your monitor so that it
can be displayed. Today's video cards have a variety of "3D" capabilities. 3D
video cards are only needed for playing games though. When playing 3D games,
the video card is the most important component.

Voltage: This is the amount of power supplied to components. CPU voltage is
the only one that we ever have any control over. Increasing the voltage can be
helpful in over clocking your CPU to a high speed. Most motherboards do not
support this as an option though.

Computer Terms

Monday, November 19, 2007

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