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Related Flashcards
Cards In This Set
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Data transfer is known as ________, which specifies how much data is
being sent per second. The speed at which data is computed is known as
Hertz, which also dictates the frequency used to transfer data.
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Bandwidth
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Other than bits and bytes and their multiples, probably the second most
significant concept to understand about computer measurements is
bandwidth, also known as __________________. Bandwidth refers to the
amount of information that can be sent or received through a computer
or network connection in one second. This can be measured in bits (with
a lower case b) or bytes (with an upper case B). For example, the
bandwidth of a USB 1.1 port running at full speed transfers a maximum
of 11 megabits per second (11 Mbps, notice the lower case b), while the
bandwidth of a USB 2.0 port running at high speed is 480 Mbps, and a
user might download 300 kilobytes
(300 KB/s, notice the upper case B) of data per second. Or an expansion
card that goes into a PCI slot could transfer a maximum of 266 MB/s.
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Data transfer rate
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Bandwidth measurements are used for measuring the performance
of serial, parallel, wired and wireless network connections, expansion
slots (PCI, PCIe, and AGP), hard disk interfaces (PATA and SATA), and
multipurpose device interfaces (SCSI, USB, and FireWire). It defines
the _____________________ that can flow through the computer.
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Amount of information
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The ___is the central point for most information.
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CPU
When you start a program, the CPU instructs the storage device to load the program into RAM. When you create data and print it, the CPU instructs the printer to output the data. |
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___________________use multiple “lanes” for data and programs, and in keeping with the 8
bits = 1 byte nature of computer information, most parallel transfers
use multiples of 8. This type of transfer take place between the following
devices:
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Parallel transfers
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For parallel transfers, many wires or traces (wire-like connections on the motherboard or
expansion cards) are needed, leading to _____.
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Interference concerns and
thick, expensive cables
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For parallel transfers, excessively long parallel cables or traces can cause data to arrive at different times. This is referred to as ___________
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Signal skew
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Differences in voltage between wires or traces can cause ______
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Jitter
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As a result of these problems some compromises have had to be included in __________________________
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Computer and system design:
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A _______________
uses a single “lane” in the computer for information transfers.
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Serial transfer
This sounds like a recipe for slowdowns, but it all depends on how fast the speed limit is on the “data highway.” |
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The following ports and devices in the computer use serial transfers:
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Serial transfers
One ___at a time is transferred to the device. |
Bit
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Serial transfers
___________________ can vary greatly, depending on the sender and receiver. |
Transmission speeds
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Serial transfers
Very few ___________ are needed in the cable and ports (one transmit, one receive, and a few control and ground wires). |
Connections
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Serial transfers
____________ can be longer with serial devices. For example, an UltraDMA/133 PATA/IDE cable can be only 18 inches long for reliable data transmission, whereas a Serial ATA cable can be almost twice as long. |
Cable lengths
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