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For the purposes of presenting speed test results, we adopt the data communications convention of k = 1000, not k = 1024. For example, 28.8k modems ran at 28800 bits per second, and 56k modems ran at 56000 bits per second.

The transfer rate expressed as kilobytes per second is based on 1024 as per data storage conventions.

Feedback received on this FAQ entry:
  • Compared with other speed tests, these results are ~8x lower. I think this indicates that the results are expressed in kiloBytes/second, not kilobits. You should revise your unit labels to kB instead of kb to make this clear. Or better yet, revise your test results to read in kilobits, like most other speed tests. It never hurts to define your units right on the results indicator, by the way. I also would like to correct all the folks who are using upper case K for kilo, like some of the previous comments. That's wrong.

    2014-08-09 13:48:14

  • Per ISO and NIST a lower case 'k' is the proper prefix for the 1000s multiplier kilo. The upper case 'K' does not represent kilo (http://physics.nist.gov/cuu/Units/prefixes.html). As was previously posted, the Kibi (Ki) prefix is used to represent 2^10, or 1024 decimal as a multiplier (http://physics.nist.gov/cuu/Units/binary.html). Also, technically "bit" is the proper abbreviation for "binary digit", not 'b', whereas 'B' is generally - but not always - understood to be an 8-bit byte. A kilobyte per second would be 1000 x 8 bits/byte = 8000 bits per second, whereas a Kibibyte per second would be 1024 x 8 bits/byte = 8192 bits per second.

    2012-11-29 01:01:22 (viasatguy See Profile)

  • The computer industry has tried to standardize the meanings of binary prefixes. There is ambiguity in how the old nomenclature is used. There is now a more precise standard that is more precise when describing bit and byte quantities. Kibibyte = 2^10 bytes = 1024 bytes Mebibyte = 2^20 bytes = 1048576 bytes and others http://en.wikipedia.org/wiki/Binary_prefix which is part of http://en.wikipedia.org/wiki/IEC_60027 This standard attempts to overcome ambiguity. Yes it is change and is annoying but it's very specific and guarantees what you write is what others will read.

    2012-03-24 21:44:57 (mrmeval See Profile)

  • Just for information, "k" meaning "kilo" should be always low case - "k", never "K". Upper case is simbol of "Kelvin", unit for absolute temperature.

    2012-02-24 08:15:33

  • lower case b means bits, upper case B means bytes. So Kb is always kilobits. Kilobyte would be KB

    2012-02-22 16:27:32

  • FYI : Kb = kilo bit KB = kilo byte Mb = mega bit MB = mega byte

    2012-01-16 09:24:13

  • Be clear. Label the Kb on the main screen to be Kilobits or Kilobytes. I'm still not clear which you mean. The 1024 vs 1000 is a detail in this context.

    2011-09-23 18:32:36

Expand got feedback?

edited by Mike See Profile
last modified: 2012-02-24 09:35:40