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Bits and Bytes are units that measures data transfer rate. In computer world,
they are often measured under binary form where everything is a function of powers of 2.

The Prefixes can apply to these two units in a similar manner of that of the metric system
yet their values can be interpreted differently by others if they happen to use the decimal system so keep that in mind.
As such, the use of the these prefixes are NOT universally adopted as of yet.
With that said, this FAQ does NOT assume full IEC adoption of the prefixes.

Here's a bit of an outline (Courtesy from Lyberty.com - Eclectic Content)

K = 1,024 ; k = 1,000 ; B = Bytes ; b= bits

Filesize (how big a file is on your computer) is usually measured in units of "KiloBytes," "MegaBytes," and "GigaBytes."

In binary usage, 'K' (uppercase) represents a multiplier of 1,024.
Other abbreviations use this same base of 1,024:

1 KB (one KiloByte) = 1,024 Bytes (approximately 1 thousand Bytes)
1 MB (one MegaByte) = 1,024 KB (approximately 1 million Bytes)
1 GB (one GigaByte) = 1,024 MB (approximately 1 billion Bytes)
1 TB (one TeraByte) = 1,024 TB (approximately 1 trillion Bytes)

Data transfer speed on the other hand is expressed in bits. In bit rates the abbreviations are as follows:

1 kbps = 1,000 bits per second
1 Mbps = 1,000,000 bits per second.
1 Gbps = 1,000,000,000 bits per second.

kbps (kilobits/sec) means thousands of bits per second
mbps or Mbps (megabits/sec) means millions of bits per second
gbps or Gbps (gigabits/sec) means billions of bits per second (where "billion"= 1,000,000,000.00")
tbps (terabits/sec) means trillions of bits per second (as in "terabit router" or "terabit speeds")
pbps (petabits/sec) means quadrillions of bits per second.

Examples:

"Gigabit Ethernet [1000Base-T] is capabile of speeds up to 1000 mbps (mega-bits per second), or 1 gbps."
"10Base-T ethernet operates at 10 mbps and uses baseband transmission methods."
"SATA II defines the architecture (SATA-300) for Serial ATA communications of up to 3 gbps."

Alternate forms:
*IEC Recent Adoptions:

**one kibibyte 1 KiB = 1024 Bytes
**one mebibyte 1 MiB = 1 048 576 Bytes
**one gibibyte 1 GiB = 1 073 741 824 Bytes

bbps = billion bits per second (where b = 1 000 000 000)
mbps = million bits per second (where m = 1 000 000)
kbps = thousand bits per second (where k = 1 000)
tbps = trillion bits per second (where t = 1 000 000 000 000) <-- (Theoretical, not yet in practice)

Here's a break down.

The use of bits in binary:

1024 bits = 1 kilobits

1024 kilobits = 1 megabit (or 1048576 bits)

**Telcos often uses the decimal
system for their transfer rates, thus:

1000 bits = 1 kilobits

1000 kilobits = 1 megabit (or 100000 bits)

***So please keep in mind that the value of the prefixes are interchangeable based on context.

Use of Bytes in binary:

1 Byte = 8 bits

1 KiloByte = 1024 Bytes = 8192 bits (or 8.192 kilobits)

1 MegaByte = 1024 KiloBytes = 8388608 bits (or 8.388608 megabits)

So with that in mind, let's apply it to our broadband internet services.

Most DSL providers now offer 1500/128

When they meant they offered 1500/128,

that is 1500 kilobits down and 128 kilobits up.

That equates to 1.5 megabits down.

In KiloBytes, a 1500 kilobit line = 183.10546875 KiloBytes

Remember that Internet Explorer calculates in Bytes
.

Applying
our general rule of thumb, if you are getting at least 80% or more of
your advertised speed then you're good and getting what you're paying
for.

80% of 1500 kilobits
= 1200 kilobits

1200 kilobits = 146.484375 KiloBytes

Again, if you are getting roughly 146 KiloBytes per second (KB/s) or more then you're getting sufficient speed of what is provisioned for you.

Be aware now that Telco territory is key to what your specific cap will be
(This applies only to DSL). Which is the reason why you will find a
variety speeds on the AOL Broadband Services.

In SBC/Pacbell territory, customers are generally offered with speeds of 1500/128 or 1500/256

In BellSouth territory, customers are generally offered with speeds of 1500/256

In Verizon Territories, customers are generally offered with 768/128

As of now AOL Cable Services are only offered through Time Warner Cable which offers speed of 2000/384.

For more information about advertised speeds on AOL DSL services, click here. For AOL Cable services, click here.


Feedback received on this FAQ entry:
  • I'll keep this feedback in place as it touches an important point that was mentioned at the beginning of the FAQ with regards to later adoptions of unit standards.

    2014-04-07 19:49:25 (Meteor Dive See Profile)

  • Sorry, but I disagree with your FAQ info. First, the proper unit abbreviation for kilo - the 1000s multiplier - is a lower case 'k', an upper case 'K' is never proper. Second, kilo always indicates a multiplier of 1000 (10^3) regardless of the unit it is applied to be it a bit, byte, meter, fortnight, etc. The Kibi (Ki) [along with Mibi, Gibi, etc] was developed with computer systems and storage in mind and represents a 1024 decimal multiplier (2^10 binary). The NIST links below will explain further, but I'm happy to provide more info as needed. http://physics.nist.gov/cuu/Units/prefixes.html http://physics.nist.gov/cuu/Units/binary.html http://www.ewh.ieee.org/soc/ias/pub-dept/abbreviation.pdf http://www.itu.int/ITU-R/index.asp?redirect=true&category=information&rlink=terminology-database&lang=en&adsearch=&SearchTerminology=&collection=§or=&language=all&part=abbreviationterm&kind=anywhere&StartRecord=1&NumberRecords=50 http://www.iso.org/iso/home/store/catalogue_ics/catalogue_detail_ics.htm?csnumber=30669 The document at the above link is copyrighted material, so I can't forward that, but you can purchase a copy for 146.00 CHF

    2012-11-29 12:39:27 (viasatguy See Profile)



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by Meteor Dive See Profile
last modified: 2014-04-07 19:45:23