Kilobyte

[Nusa]

It's like that old argument between Imperial and Metric - the US will NEVER go metric.  Sure, the science people will use metric but it's worth noting that Structural Engineering is done in kips.  Electrical Engineering and most Mechanical Engineering is also done in imperial units.  Air motion is in CFM - cubic feet per minute.  Water flow is in GPM - gallons per minute.  And that's the way it's going to stay!

Metrification IS happening in the US by default, it's just going to take a long time, or at least until more of the older generations (likely including myself) die off. The US really is the odd man out, world-wide, being the only significant hold-out. Most industries are allowed to voluntarily convert any time they want. For instance, in the food industry, it's been a long time since you've seen 2-quart soda bottles. But 2-liter bottles are everywhere! Virtually everything food-related is dual-labeled, no matter what its base size is.

[David Hess]

A kilo- is 1000. Please do not arbitrarily redefine systems which existed long before your use case.

Byte is not an SI unit.  Please do not arbitrarily redefine systems which existed long before your use case.

[David Hess]

I will start using K=1000 for memory when they start selling 2767108864 EPROMs and hard drives start using 500 and 4000 byte sectors.

[Monkeh]

I will start using K=1000 for memory when they start selling 2767108864 EPROMs and hard drives start using 500 and 4000 byte sectors.

Nobody is asking you to use multiples of 1000. Just to use a prefix which correctly expresses what you're doing, instead of a misappropriated one which leads to confusion.

[David Hess]

But you can not complain if a 1TB hardisk is really 10^12 bytes and not 2^40 bytes 

Well, you could, because according to the common industry language, it's misleading at best. And that said, when a HD manufacturer says 1TB, it's often not even exactly 10^12 bytes, but just something close to that.

The hard drive manufacturers made the change before Eternal September so you will not find much on the internet about it.  Initially they measured capacity like the memory manufacturers but then one got the bright idea of using 1000 in place of 1024 which made their capacity seem greater and the rest is history.  There were complaints about it in the trade magazines at the time.

[David Hess]

I will start using K=1000 for memory when they start selling 2767108864 EPROMs and hard drives start using 500 and 4000 byte sectors.

Nobody is asking you to use multiples of 1000. Just to use a prefix which correctly expresses what you're doing, instead of a misappropriated one which leads to confusion.

Many applications require it now and the mass storage manufacturers do.

How about having everybody stop using bytes and instead use Libraries of Congress?  Or is that an SI unit also?

[Monkeh]

I will start using K=1000 for memory when they start selling 2767108864 EPROMs and hard drives start using 500 and 4000 byte sectors.

Nobody is asking you to use multiples of 1000. Just to use a prefix which correctly expresses what you're doing, instead of a misappropriated one which leads to confusion.

Many applications require it now

Such as?

and the mass storage manufacturers do.

Yes, well, at least they're using the prefix correctly. I do wish they'd just switch to the more appropriate prefix and with it the nominal sizes, but..

[Kjelt]

Byte is not an SI unit.

Correct it is defined as the smallest addressable unit of memory and can be anything from 6-48 bits.
You want to go back to that definition?

Luckiliy the IEC has defined it to "usually 8 bits" in 1993 in ISO/IEC 2382-1:1993

https://en.m.wikipedia.org/wiki/Byte

But perhaps our american friends want to deviate from that to ? 

Then in systems with parity bits one usually defines a byte as 9 bits , it is a mess isn't it ?
Perhaps we should abandon the byte and only use bits 

We poor oldtimers, living with JEDEC, were doing just fine until the IEC came along.  We knew what we meant when we said kilobyte or megabyte. 

What did Jedec define please give me the standard.
Before ISO/IEC 2382-1:1993 it was undefined, at least the common use was as much bits as a character needed in an architecture so between 6 and 48 bits.

[rstofer]

Metrification IS happening in the US by default, it's just going to take a long time, or at least until more of the older generations (likely including myself) die off.

Those highway signs in km didn't last long, did they?

We use imperial units and we have been to the moon and back.  The rest of the world uses metric and can't get out of Earth's orbit.  See the correlation?  The metric system stunts technological growth.

[SiliconWizard]

We use imperial units and we have been to the moon and back.  The rest of the world uses metric and can't get out of Earth's orbit.  See the correlation?  The metric system stunts technological growth.

 

[rstofer]

Luckiliy the IEC has defined it to "usually 8 bits" in 1993 in ISO/IEC 2382-1:1993

1993 is 'Johnny come lately' in the computer world.  We were using byte, kilobytes and megabytes for decades before IEC came along.  Somehow we managed to build stuff without getting confused.  We didn't need 'kibbles'.

FWIW, the Baudot code for characters was 5 bits (plus a start and stop bit).  Of course there had to be a couple of shift characters to shift between Letters and Figures.  It was invented in 1870 and Baud is named for the inventor.

The CDC 6400 used a 60 bit word and I'm not aware that it could be fetched in anything other than full width words.  There were  30 bit instructions and 15 bit instructions packed in 60 bit words.  Ten chars per word and 18 bits for addressing.  Extracting a char from the middle of a 60 bit word was a problem for years before CDC added the 'compare move' unit to address the needs of business programmers using COBOL.

[Monkeh]

Metrification IS happening in the US by default, it's just going to take a long time, or at least until more of the older generations (likely including myself) die off.

Those highway signs in km didn't last long, did they?

We use imperial units and we have been to the moon and back.  The rest of the world uses metric and can't get out of Earth's orbit.  See the correlation?  The metric system stunts technological growth.

Yeah. You went to the moon using a metric computer.

Please grow up.

[IanB]

I always thought that capitals were used for multiplying prefixes and lower case for divider prefixes. i have had this problem before being assured that it's lower case for kbps but i don't get it because no one uses mbps do they? T, G, M, K, unit, m, µ, n, p, Am I missing something here?

Yes, you are missing something. There are a set of prefixes used for SI (Système international d'unités or International system of units), which are standardized for use within this system. You have (T)era, (G)iga, (M)ega, (k)ilo, m(illi), (μ)icro, (n)ano, (p)ico, etc. (Notice how they ran out of m's and had to switch to Greek?)

This set of prefixes are used for quoting physical measurements in the SI (metric) system.

Other prefixes are used in other contexts. For example, in U.S. customary usage, M often means 1000, and MM means one million. So, for example, 1 MMbbl/d is one million barrels per day, and 1 MMscf/h is one million standard cubic feet per hour.

Therefore, we can question whether "bits" in computing are part of the SI system, and should use SI prefixes. Clearly there are other historical conventions with other usages. Since computing uses powers of two (for good reasons), the convention since the beginning has been that in computing the "K" and "M" prefixes are powers of two, namely 2¹⁰ and 2²⁰.

According to which culture and convention one is working with, "M" could mean 1 000 000 , 1000, or 1024.

[David Hess]

Byte is not an SI unit.

Correct it is defined as the smallest addressable unit of memory and can be anything from 6-48 bits.
You want to go back to that definition?

That is a word.  Words have machine dependent width.

Luckily the IEC has defined it to "usually 8 bits" in 1993 in ISO/IEC 2382-1:1993

https://en.m.wikipedia.org/wiki/Byt

So having screwed up, the IEC doubles down and gets involved redefining established standards.  "Usually 8 bits" is a terribly useful definition.  Can I blame the IEC for furthering type confusion in programming?

[Nusa]

Metrification IS happening in the US by default, it's just going to take a long time, or at least until more of the older generations (likely including myself) die off.

Those highway signs in km didn't last long, did they?

We use imperial units and we have been to the moon and back.  The rest of the world uses metric and can't get out of Earth's orbit.  See the correlation?  The metric system stunts technological growth.

Classic example of a strawman argument. But since we're on the subject, Nasa went metric about 30 years ago, at least for new technology. And the claim that only we can leave the earths orbit is simply false: https://en.wikipedia.org/wiki/List_of_Solar_System_probes

[rstofer]

Yeah. You went to the moon using a metric computer.

I worked in a machine shop that built a LOT of ground support equipment for NASA circa '65.  All of the dimension were imperial.  AFAIK, none of the machine tools had metric scales.

[amyk]

256MB of RAM is 2^28 bytes, not 256 * 10^6 bytes, and contains exactly 2^(28-12) = 2^16 4KB pages. Everything is powers of 2 and calculates nicely.

With hard drives, sectors are still a power of 2 in size (usually 512 = 2^9, newer ones may have 4K = 2^12 physical sectors) but you get cheated, because you can't e.g. write all the bytes in 4GB of RAM exactly 10 times to a 40GB hard drive.

With flash storage, it used to be the case that a flash drive would be a precise power of 2 size (e.g. a 64MB U disk would really store 2^26 bytes), but now they are starting to become "non-binary" again...

Don't even get me started on those stupid-sounding binary prefixes

[Rerouter]

the non binary of flash drives came from needing a fraction of the flash memory to swap out as bad blocks formed, and to get marginal memory over the line, so while my SSD has enough flash chips to be exactly 128GiB, it ends up 120GB with a decent volume hidden for caching and bad block management.

[hamster_nz]

Comms bandwidth is (nearly) always in metric.

So a 8Gb/s link will never transfer a gigabyte per second (even before protocol overhead).

[SparkyFX]

the non binary of flash drives came from needing a fraction of the flash memory to swap out as bad blocks formed, and to get marginal memory over the line, so while my SSD has enough flash chips to be exactly 128GiB, it ends up 120GB with a decent volume hidden for caching and bad block management.

And the file system will take an additional toll for the organizational part (journaling, file information), now try explaining to the average buyer why not all specified storage can be used (the impact is iirc higher than kB/kiB).

A useful answer to these problems would be: express yourself in a way you can not be misunderstood, at least know the difference between the two. That´s more important than questioning the legitimacy of a unit.

Actually there could be a workaround by stating the width of the address in bits, because "the nearest to 1000" is a decimal approach within a binary system, which does not make much sense in the first place. OTOH it might not tell you the amount of addressable space.

Comms bandwidth is (nearly) always in metric.

The telecommunication people relate their specs to Hertz, which would be impractical using a binary system otherwise.

[madires]

It's like that old argument between Imperial and Metric - the US will NEVER go metric.  Sure, the science people will use metric but it's worth noting that Structural Engineering is done in kips.  Electrical Engineering and most Mechanical Engineering is also done in imperial units.  Air motion is in CFM - cubic feet per minute.  Water flow is in GPM - gallons per minute.  And that's the way it's going to stay!

Old town halls over here have some special wall stones defining how large the local cubit is.

[madires]

I will start using K=1000 for memory when they start selling 2767108864 EPROMs and hard drives start using 500 and 4000 byte sectors.

Lower case k!

[rs20]

256MB of RAM is 2^28 bytes, not 256 * 10^6 bytes, and contains exactly 2^(28-12) = 2^16 4KB pages. Everything is powers of 2 and calculates nicely.

With hard drives, sectors are still a power of 2 in size (usually 512 = 2^9, newer ones may have 4K = 2^12 physical sectors) but you get cheated, because you can't e.g. write all the bytes in 4GB of RAM exactly 10 times to a 40GB hard drive.

"Why doesn't 4GB fit into 40GB ten times?" "Because GB means different things for RAM and Hard drives"

Let me show how I would write this:

256MiB of RAM is 2^28 bytes, not 256 * 10^6 bytes, and contains exactly 2^(28-12) = 2^16 4KiB pages. Everything is powers of 2 and calculates nicely.

With hard drives, sectors are still a power of 2 in size (usually 512 = 2^9, newer ones may have 4096 = 2^12 physical sectors) but you get cheated, because you can't e.g. write all the bytes in 4GiB of RAM exactly 10 times to a 40GB hard drive.

"Why doesn't 4GiB fit into 40GB ten times?" "Because 40GB / 4GiB = 9.31..."

I understand as well as anyone that there's a huge backlog of documentation using the 1MB=2^20 bytes definition lying around. But it's fabulous being able to concisely jump between 2^30 and 10^9 as simply as jumping between "GiB" and "GB", and even the most ardently change-averse among you must surely concede that you can read + understand my version perfectly well, even if you think I'm weird. I'd wager most people would understand the point being made more rapidly as well.

So for me, that's all there is to it. I choose to communicate in the clearest and most unambiguous way possible, and so I personally make use of the new power-of-2 prefixes precisely because they are completely unambiguous. I'm not sure how whinging and whining about how weird "Mebibyte" sounds makes the world a better place in any way; like it or not, it's here to stay.

Fun side question: what is the proposed new way to represent plain integers, like 4096, succintly? 4Ki? 

[Jan Audio]

I dont wanted to start a fight, just a poll, where is the add poll button ?

[GeorgeOfTheJungle]

The button "new poll" is next to the "new topic" button: