kbit vs. Kbit kByte vs. KByte (was BW Calc) [7:65211]
Wow! I knew there was confusion out there about this, but I didnt realize just how much (even on my part it would seem). Heres one possible source of clarification: http://www.speedguide.net/Cable_modems/bandwidth.shtml and another: http://www.scotsnewsletter.com/best_of/dtrct.htm (not this Scott's newsletter by the way - I just happened across it doing a yahoo search on the matter) The consensus seems to be that there should be made a distinction between a binary Kilo (with a capital K) and a decimal kilo (with a lower-case k). This, I think, was already well-established and agreed to but it sure is easy to get sloppy with that capitalization and terminology. kbit = 1,000 bits (decimal 10^3) kByte = 1,000 bytes (decimal 10^3) Kbit = 1,024 bits (binary 2^10) KByte = 1,024 bytes (binary 2^10) As I understand it, most modern hard drives are now rated in decimal format (Im pretty sure it used to be binary, but Ive read in several different places that the industry migrated to decimal sometime back -- probably as a marketing gimmick). That is, 1 kByte (or even KByte in this special case) of storage actually equals 1,000 Bytes or 8,000 bits instead of 1,024 Bytes or 8,192 bits. Memory is apparently still rated in binary Kilo bits/Bytes. That is, 1 KB of memory is 1,024 Bytes or 8,192 bits. All WAN connections always have been and still are rated in decimal format. That is, 1 kbps equals 1,000 bits/sec and 1 kB equals 1,000 Bytes (or 8,000 bits)/sec. I'm not aware of throughput ever having been expressed in binary Kbits or KBytes (at least not in the telecom world). Maybe computer geeks did that, but it only served to confuse the matter more if they did. If a download test were to return results in true binary KBytes/sec, you would first have to multiply that number of KBytes by 1,024 and then multiply by 8 to get the true decimal number of bits/sec. Perhaps tests some do. Perhaps some dont. Probably its a mess of a mix that resulted from all this confusion. Software weenies still seem to deal with binary Kilo, regardless of whether its bits or Bytes. But Im not one of them, so I cant make this last statement definitively. Sheesh. Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=65211t=65211 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: kbit vs. Kbit kByte vs. KByte (was BW Calc) [7:65211]
Here's a perfectly illustrative example of how common it is to jumble all this terminology up... I often use a download test site at PC Pitstop: http://www.pcpitstop.com/internet/Bandwidth.asp I ran a quick download test that transferred a 500 KB block of text to my machine. It took 2.744 seconds to complete. Thus, the result was returned as 1458 Kb/s. Here's the math: (assuming decimal) 500 * 1000 * 8 = 4,000,000 bits / 2.77 seconds = ~1,458,000 bits/sec = ~1458 decimal kbits/sec or ~1423 binary Kbits/sec Now... (assuming binary) 500 * 1024 * 8 = 4,096,000 bits / 2.77 seconds = ~1,478,000 bits/sec = ~1478 decimal kbits/sec or ~1443 binary Kbits/sec So, in spite of the fact that they are using the binary upper-case K throughout, they are obviously meaning the decimal lower-case k, which makes sense given that throughput is expressed that way. Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=65220t=65211 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: kbit vs. Kbit kByte vs. KByte (was BW Calc) [7:65211]
This is all very well but sometimes when people write 500 they really mean 512, so where does that leave you ?8-) Marc s vermill wrote: Here's a perfectly illustrative example of how common it is to jumble all this terminology up... I often use a download test site at PC Pitstop: http://www.pcpitstop.com/internet/Bandwidth.asp I ran a quick download test that transferred a 500 KB block of text to my machine. It took 2.744 seconds to complete. Thus, the result was returned as 1458 Kb/s. Here's the math: (assuming decimal) 500 * 1000 * 8 = 4,000,000 bits / 2.77 seconds = ~1,458,000 bits/sec = ~1458 decimal kbits/sec or ~1423 binary Kbits/sec Now... (assuming binary) 500 * 1024 * 8 = 4,096,000 bits / 2.77 seconds = ~1,478,000 bits/sec = ~1478 decimal kbits/sec or ~1443 binary Kbits/sec So, in spite of the fact that they are using the binary upper-case K throughout, they are obviously meaning the decimal lower-case k, which makes sense given that throughput is expressed that way. Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=65236t=65211 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
