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SPEED (and MEASUREMENT):  Here are some useful speed and measurement figures.  These numbers are as accurate as possible, but are recited mainly for COMPARISON and ESTIMATION purposes, i.e. how much faster one type of connection would be over another.   BEWARE:  All numbers are “theoretical” and are estimates - for calculating practical usage, divide by as much as half!

Definition links are highlighted in BLUE.

For an answer to the general question “What Makes A Computer Fast?” click HERE.

Wireless Transfer Speeds:

80211b - 11Mbps

80211g - 54Mbps

80211n - 300 Mbps

802.11ac - 1.3 Gbps

Cable Transfer Speeds:

POTS (TEL) - 52Kbps

56L V90, 92 Tel Modem - 56kbps

Mobile Phone - 14.4Kbps or more

DSL - 128Kbps or more

ISDN - 64kbps

Cable Broadband - 128Kbps or more

ethernet - 10/100Mbps

gigabit ethernet - 1000Mbps


    USB1 - 1.5Mbps

    USB2 - 12Mbps

    High Speed USB2 - 480Mbps

    USB 3 - 5Gbps

    USB 3.1 - 10Gbps

    [Power Over USB - up to 100W]

Serial - 9600bps

Parallel/Centronics - 4Mbps/8Mbps

Bluetooth 1.1 - 1Mbps

Bluetooth 2.0+EDR - 4Mpbs

Near Field Communication - .424Mbps

Wi-Fi - 240Mpbs

WiMax - 75bps

Firewire 1 - 400Mbps

Firewire 2 - 800Mbps

Thunderbolt - 10Gbps [Channel 1 - 1.3 HDTV connection; Channel 2 - HDMI 4k; Channel 3 ULTRA HDTV]


Click HERE for KISS, a promising new technology which promises transfer speeds of 6Gps.

IDE - 60Mbps


    Rev. 1 - 1.5Gbps

    Rev. 2 - 3Gbps

    Rev. 3 - 6Gbps

    Express - 8Gbps - 16Gbps

SATA and IDE compared

SCSI 5-80Mhz, depending on bus speed

PCI - 32 bit/66Mhz - 2133Mbps

PCI Express - 2000Mbps or more

Memory Measurement Units: >>>>>>>>>

See Bits & Bytes for more

bit = 1 unit

byte = 8 bits

megabyte = 1024bytes

gigabyte = 1024 megabytes

terabyte = 1024 gigabytes

Storage Media:

3” Floppy - 1.44Mb

CD - 700Mb

DVD - 4.7Gb, 7.0Gb

SD - 128Mb - 128Gb

>>For more DVD speeds, see CD/DVD.

Travan Tape - 120Mb or more

Zip - 100Mb

Jazz - 250Mb

Compact Flash 1 - up to 512Mb or more

Compact Flash 2 - Up to 8Gb or more

USB - 4Gb  - 64Gb or more (see also Media)

Disk Read Speeds:

Desktop - 7200rpm, 9ms seek

Laptop - 5400, 5ms seek

Enterprise - 10-15,000rpm, 4.5ms seek


Data SPEEDS are usually described in terms of BITS:

1,024 bits = 1 Kilobit

1,024Kb = 1 Megabit

1,024Mb = 1 Gigabit

1,024Gb = 1 Terabit

Data STORAGE is usually described in terms of BYTES:

8 bits = 1 byte

1,024 bytes = 1 Kilobyte

1,024KB = 1 Megabyte

1,024MB = 1 Gigabyte

1,024GB = 1 Terabyte

So, for example, a 10 Gbps connection would allow you to transfer 75GB of data over the course of a minute, or the equivalent of about 110 full CDs worth of music.  5 hours of web browsing consumes about 100Mb of data usage, while 1 hour of streaming video consumes about 240Mb of data usage.

Wikipedia has a page with an exhaustive compilation of device bit rates.

The FORMAT in which an image file is saved directly effects the SIZE of the file [Chart from].  Particularly when scanning something for attachment to e-mails, if you don’t save at 150 -300 dpi (which is all your monitor displays anyway), you can end up with a 5Mb file when it should be only about 10Kb, slowing or even blocking transmission.  Watch your settings:

Image file formats compared


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