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HP Forum Archive 21

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Binary versus Decimal prefixes
Message #1 Posted by bill platt on 21 Apr 2013, 8:59 p.m.

While thumbing through an NIST document, I came across the following:

"These SI prefixes refer strictly to powers of 10. They should 
not be used to indicate powers of 2 (for example, one kilobit represents 
1000 bits and not 1024 bits). The IEC has adopted
prefixes for binary powers in the international standard IEC 60027-2:
2005, third edition, Letter symbols to be used in electrical
technology  Part 2: Telecommunications and electronics. 
The names and symbols for the prefixes corresponding 
to 2^10, 2^20, 2^30, 2^40, 2^50, and 2^60 are, respectively: kibi, Ki;
 mebi, Mi; gibi, Gi; tebi, Ti; pebi, Pi; and exbi, Ei. 
Thus, for example, one kibibyte would be written: 
1 KiB = 2^10 B = 1024 B, where B denotes a byte.
Although these prefixes are not part of the SI, they should be 
used in the field of information technology to avoid the 
incorrect usage of the SI prefixes."

While it seems a good idea in theory, how the hell is this going to stick? We've been saying "kilobytes" for 30 years and we know that is 1024...

I'm not a computer dude (far from it). If you are, what do you think of this?

Edited: 21 Apr 2013, 9:01 p.m.

      
Re: Binary versus Decimal prefixes
Message #2 Posted by bhtooefr on 21 Apr 2013, 9:08 p.m.,
in response to message #1 by bill platt

Personally, I like reducing the ambiguity (although I don't like the inconsistency that kibi is abbreviated Ki, whereas kilo is abbreviated k (then again, I get that it's resolving the lowercase less than 10^0, uppercase greater than 10^0 inconsistency in SI)), although I don't like that it came to it.

Personally, I've adopted the binary prefixes (except I use ki instead of Ki). And, there is no such thing as a 1.44 MB or 1.44 MiB floppy disk - they're 1,474,560 B, 1440 kiB, 1.4063 MiB, or 1.47456 MB. 1.44 only works if you combine prefixes, as in, 1.44 kkiB.

      
Re: Binary versus Decimal prefixes
Message #3 Posted by Garth Wilson on 21 Apr 2013, 11:08 p.m.,
in response to message #1 by bill platt

I think the context makes it clear enough. For example, if you say kilobytes, it it assumed you mean sets of 1024 bytes, whereas if you say kilohms, it is assumed you mean sets of a thousand ohms.

            
Re: Binary versus Decimal prefixes
Message #4 Posted by Walter B on 22 Apr 2013, 12:08 a.m.,
in response to message #3 by Garth Wilson

+1

d:-)

            
Re: Binary versus Decimal prefixes
Message #5 Posted by Eric Smith on 22 Apr 2013, 1:10 a.m.,
in response to message #3 by Garth Wilson

Clear enough by context? So if you say gigabytes, are you talking about units of 1,000,000,000 bytes, or 1,073,741,824 bytes?

                  
Re: Binary versus Decimal prefixes
Message #6 Posted by Walter B on 22 Apr 2013, 1:19 a.m.,
in response to message #5 by Eric Smith

Quote:
So if you say gigabytes, are you talking about units of 1,000,000,000 bytes, or 1,073,741,824 bytes?
As far as I obeserved in the real world 1kB = 1024 Bytes, 1MB = 1000kB, 1GB = 1000MB = 1 024 000 000 Bytes, 1TB = 1000GB, etc. Not fully coherent, but far better than thumbs and feet.

d:-)

                        
Re: Binary versus Decimal prefixes
Message #7 Posted by bhtooefr on 22 Apr 2013, 8:31 a.m.,
in response to message #6 by Walter B

It depends on the sub-context, though. When you're using

When you're talking about hard drive capacity (and network speeds - 1 gigabit per second is, IIRC, 1,000,000,000 bits per second):

1 kB = 1000 B 1 MB = 1000 kB 1 GB = 1000 MB 1 TB = 1000 GB

When you're talking about solid state storage, bus speeds, RAM, really anything that ISN'T hard drives or networks:

1 kB = 1024 B 1 MB = 1024 kB 1 GB = 1024 MB 1 TB = 1024 GB

So, there's tons of ambiguity.

                              
Re: Binary versus Decimal prefixes
Message #8 Posted by Matt Agajanian on 26 Apr 2013, 2:32 p.m.,
in response to message #7 by bhtooefr

I gotta agree on this one. Computer-related terminology should remain consistent with its binary-based foundations. Thus, I whole-heartedly concur that its kilo, mega, giga, etc. prefixes should remain in agreement with its binary meanings. In both, hardware drives and software, yes, since they are also computer related, these too should retain the binary relationships.

Although, in terms of clock and processor speed, the K, M and G prefixes should adhere to their decimal/base ten underpinnings (i.e. KHz, MHz, GHz) because these technologies of mechanics and electronics have always been measured on the decimal/base 10 scale.

Edited: 26 Apr 2013, 2:35 p.m.

                                    
Re: Binary versus Decimal prefixes
Message #9 Posted by Walter B on 26 Apr 2013, 4:49 p.m.,
in response to message #8 by Matt Agajanian

Quote:
Although, in terms of clock and processor speed, the K, M and G prefixes should adhere to their decimal/base ten underpinnings (i.e. KHz, MHz, GHz) because these technologies of mechanics and electronics have always been measured on the decimal/base 10 scale.
FYI, it's kHz still with a lower case prefix k. Please look here.

d:-I

                                          
Re: Binary versus Decimal prefixes
Message #10 Posted by Gerson W. Barbosa on 26 Apr 2013, 5:15 p.m.,
in response to message #9 by Walter B

I remember once I got a penalty in one otherwise perfect exam because the professor thought I had written KVA instead of kVA. Apparently the k's upper arm did not look small enough to him. Oh, well...

                                          
Re: Binary versus Decimal prefixes
Message #11 Posted by Garth Wilson on 26 Apr 2013, 6:36 p.m.,
in response to message #9 by Walter B

On another forum, I keep seeing mhz or mHz, when they actually meant MHz, a billion times as many cycles per second as they said. Our production people kept labeling capacitors with MFD, and I explained that that would be an automobile-sized capacitor, and if they couldn't write the lower-case Greek letter mu for "micro," then please make it a low-case "u" and write 100uF for example, not one hundred megafarad!

                                                
Re: Binary versus Decimal prefixes
Message #12 Posted by Kiyoshi Akima on 26 Apr 2013, 10:57 p.m.,
in response to message #11 by Garth Wilson

I remember decades ago seeing a press release for a new modem chip suitable for laptops because of its power consumption. It was listed as using some number of MW (megawatts) instead of mW (milliwatts). Not the kind of thing I'd want on my lap, even in a Colorado winter.

                                                      
Re: Binary versus Decimal prefixes
Message #13 Posted by Joe Horn on 26 Apr 2013, 11:24 p.m.,
in response to message #12 by Kiyoshi Akima

Quote:
I remember decades ago seeing a press release for a new modem chip suitable for laptops because of its power consumption. It was listed as using some number of MW (megawatts) instead of mW (milliwatts). Not the kind of thing I'd want on my lap, even in a Colorado winter.
If you really want to warm up a room, borrow the 5 TW laser pointer that the HHC 2009 website claims was among the audiovisual supplies for the presenters: http://hhuc.us/2009/talk.htm This year they only have a puny 200 mW laser pointer.
                                                            
Re: Binary versus Decimal prefixes
Message #14 Posted by Patrice on 27 Apr 2013, 12:26 a.m.,
in response to message #13 by Joe Horn

Quote:
borrow the 5 TW laser pointer
Do you think I can borrow the battery to power my Delorean ? :)
                                                      
Re: Binary versus Decimal prefixes
Message #15 Posted by Kiyoshi Akima on 26 Apr 2013, 11:33 p.m.,
in response to message #12 by Kiyoshi Akima

I take it back. Upon further recollection, the press release actually said "megawatts" and not just "MW." One of the hardware types did some research and determined that Hoover Dam could power a number of these, a number in the single digits.

                                          
Re: Binary versus Decimal prefixes
Message #16 Posted by Matt Agajanian on 27 Apr 2013, 1:02 a.m.,
in response to message #9 by Walter B

Thanks for the clarification.

            
Re: Binary versus Decimal prefixes
Message #17 Posted by David Hayden on 22 Apr 2013, 6:56 a.m.,
in response to message #3 by Garth Wilson

The context would be clear except for marketing people. I believe disk sizes are always quoted using powers of 10 instead of powers of 2 now since the power of 10 number is bigger.

                  
Re: Binary versus Decimal prefixes
Message #18 Posted by bill platt on 28 Apr 2013, 2:19 p.m.,
in response to message #17 by David Hayden

Perhaps that explains why I keep feeling ripped off. I alway end up with 900 something in my 1TB drives :-(

      
Re: Binary versus Decimal prefixes
Message #19 Posted by Maximilian Hohmann on 22 Apr 2013, 2:50 a.m.,
in response to message #1 by bill platt

Good morning!

Quote:
...Although these prefixes are not part of the SI, they should be used ...

As long as half of the world still uses miles and feet and inches and gallons and pounds (which have never been part of SI and were supposed to be made obsolete 150 years ago) I think we need not worry about prefixes that only "should" be used ;-)

BTW: I have never before heard of these binary prefixes (and I have been working in IT for quite some time!) so we probably can suppose that the general public hasen't heard of them either. It would generate quite some confusion if they were introduced now!

            
Re: Binary versus Decimal prefixes
Message #20 Posted by Paul Dale on 22 Apr 2013, 3:00 a.m.,
in response to message #19 by Maximilian Hohmann

There are only two countries that officially use feet and inches and gallons and pounds: the USA and Liberia. Additionally Berma/Myanmar uses their own quite different system. The rest of the world is committed to the metric system. However, much of the world is well behind Europe in this and needs another hundred or two years to full convert.

e.g. Australia has officially been metric since 1970, however I can purchase 8' x 1200mm wall panels here and I learned both system at school in the 1970s.

- Pauli

      
Re: Binary versus Decimal prefixes
Message #21 Posted by Dave Britten on 22 Apr 2013, 11:50 a.m.,
in response to message #1 by bill platt

How about we just repeat the unit to signify magnitude? 2^(10*(n-1))

So 1 bytebyte = 1024 bytes, 1 bytebytebyte = 1048576 bytes, etc.

            
Re: Binary versus Decimal prefixes
Message #22 Posted by Eddie W. Shore on 27 Apr 2013, 10:56 a.m.,
in response to message #21 by Dave Britten

Quote:
How about we just repeat the unit to signify magnitude? 2^(10*(n-1))

So 1 bytebyte = 1024 bytes, 1 bytebytebyte = 1048576 bytes, etc.


This is a good idea. To me, using metric prefixes means powers of 10.

            
Re: Binary versus Decimal prefixes
Message #23 Posted by Walter B on 27 Apr 2013, 11:22 a.m.,
in response to message #21 by Dave Britten

Like "two to two to Toulouse"? Language was once invented for better understanding - long time before some languages arose.

d;-/


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