Why there is no unit for memory recognised by SI

[Abhishek kumar]

As we all know that there is 7 fundamental units and rest can be delivered for physical Quantities.why there is no any define unit for memory element.Now these days all around us we can see electronic systems which have memory element and memory element store data to measures data we have byte,bit,kilobytes,megabytes...
Then why these are not recognised by the International system of units as fundamental or derived unit?

 

[BvU]

Fundamental to what ? Derived from what ?
There's no physics in it. Just like in something like 'value' with SI unit grams of gold ?

 

[Abhishek kumar]

Fundamental to what ? Derived from what ?
There's no physics in it. Just like in something like 'value' with SI unit grams of gold ?

I mean to say that there should be unit for memory like KB,MB,GB

 

[BvU]

The unit would be the b, the bit. And that is a counter, not a dimension.

All that comes from SI is the multiplier. I don't know the capital K, only the lower case k for kilo (1000)

I sure wish folks would ever come to understand the difference between kB and kb (8192 and 1024 bytes, respectively). Especially the commercial folks and the journalists...

 

[cjl]

I sure wish folks would ever come to understand the difference between kB and kb (8192 and 1024 bytes, respectively). Especially the commercial folks and the journalists...

If you're going to be pedantic, you should really also note that kB and kb are 8000 and 1000 bytes, respectively, and the values you mention (8192 and 1024) are kiB and kib.

 

[Abhishek kumar]

KB=1024bytes=8192bits

 

[f95toli]

I mean to say that there should be unit for memory like KB,MB,GB

There are, but these are governed by different standards. The SI is a system for physical measurements (governed by BIPM); units used in e.g. telecom are governed by standards published by other organizations (e.g. ETSI or ANSI) and these presumably include definitions for units like GB

Note that there are LOTS of commonly used units that are not part of the SI; e.g. the definition of pH is not (directly) covered by the SI but is published by other organizations (presumably IUPAC or similar)

 

[cjl]

Nope, that's the kiB. Kilo is an SI prefix, and means 1000.

 

[Abhishek kumar]

Nope, that's the kiB. Kilo is an SI prefix, and means 1000.

May be you are correct but as i studied
in electronics we calcute in form of 2^10.

 

[DrGreg]

May be you are correct but as i studied
in electronics we calcute in form of 2^10.

See kibibyte.

 

[I like Serena]

Oh my.

The unit would be the b, the bit. And that is a counter, not a dimension.

All that comes from SI is the multiplier. I don't know the capital K, only the lower case k for kilo (1000)

I sure wish folks would ever come to understand the difference between kB and kb (8192 and 1024 bytes, respectively). Especially the commercial folks and the journalists...

kB is kilobyte, which is (usually) 8000 bits, and not 8192 bytes.
And kb is kilobit, which is 1000 bits, and not 1024 bytes.

If you're going to be pedantic, you should really also note that kB and kb are 8000 and 1000 bytes, respectively, and the values you mention (8192 and 1024) are kiB and kib.

That should be KiB respectively Kib.

Nope, that's the kiB. Kilo is an SI prefix, and means 1000.

KiB, not kiB.

May be you are correct but as i studied
in electronics we calcute in form of 2^10.

That may have once been true, in the era of hands and thumbs and pounds.
But no more.
It has been standardized.
k is really kilo for 1000. And M is really mega for 1000000. We do not obscure powers of 2 any more without using a proper and dedicated prefix for it (Ki respectively Mi).
Note that disk sizes and bit transfer rates have never been in powers of 2, although many people thought they were. That made for a nice sales pitch where those seemed larger than they actually were.
It's only memory that was in powers of 2.

 

[Abhishek kumar]

Oh my.
kB is kilobyte, which is (usually) 8000 bits, and not 8192 bytes.
And kb is kilobit, which is 1000 bits, and not 1024 bytes.
That should be KiB respectively Kib.
KiB, not kiB.
That may have once been true, in the era of hands and thumbs and pounds.
But no more.
It has been standardized.
k is really kilo for 1000. And M is really mega for 1000000. We do not do obscure powers of 2 any more without using a proper and dedicated prefix for it (Ki respectively Mi).
Note that disk sizes and bit transfer rates have never been in powers of 2, although many people thought they were. That made for a nice sales pitch where those seemed larger than they actually were.
It's only memory that was in powers of 2.

Binary bytes are obsolete now for memory unit?

 

[BvU]

It has been standardized

Any references up to PF standards ?

 

[I like Serena]

Binary bytes are obsolete now for memory unit?

One byte is defined by IEC/80000-13 as 8 bits.

Any references up to PF standards ?

The unit was established by the International Electrotechnical Commission (IEC) in 1998,[2] has been accepted for use by all major standards organizations, and is part of the International System of Quantities.[3]

[2] International Electrotechnical Commission (January 1999), IEC 60027-2 Amendment 2: Letter symbols to be used in electrical technology - Part 2: Telecommunications and electronics
[3] "IEC 80000-13:2008". International Organization for Standardization. Retrieved 2013-07-21.
​

And I've just noticed that it's now also in the joint ISO/IEC 80000 standard.

 

[BvU]

Thanks. Must have overlooked it in 50 years of working with computers
Wonder if the kibihertz will last ...

And the Wiki lemma

This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources.

(Link says thte thing is under review since 2009 ?)

 

[I like Serena]

Thanks. Must have overlooked it in 50 years of working with computers
Wonder if the kibihertz will last ...

And the Wiki lemma
(Link says the thing is under review since 2009 ?)

Indeed.
Just checked, and found for starters here, that the first item ISO 80000-1 is listed as having status Published since 2009.
Looks as if that status column is severely outdated.
Ah well, at least that is something I or anyone else can fix. ;)
Just did, and found that the last one, Telebiometrics related to human physiology, was actually withdrawn.
All the others were published in the year listed.

 

[I like Serena]

Oh wait. Apparently we've misinterpreted the status 'under review', which was correct after all.
That's actually a status that comes after 'published', and just means that after 5 years or so a standard is put under review to be revised. The first one has been under review since 2013.
So I've reverted my changes and just updated the Telebiometrics standard to say 'withdrawn'. Its status was empty before.

 

[newjerseyrunner]

Binary bytes are obsolete now for memory unit?

Depends on what you are buying.

If you buy a 500GB magnetic hard drive, you have bought 500 billion bytes.
If you buy a 256GB SSD, you have bought 256*2^30 bytes.

Marketing doesn't care about your semantics, nor do they care what you studied. They use words colloquially. How much food did you eat today? 2000 calories? Did you mean kilocalories?

 

[I like Serena]

Depends on what you are buying.

If you buy a 500GB magnetic hard drive, you have bought 500 billion bytes.
If you buy a 256GB SSD, you have bought 256*2^30 bytes.

Marketing doesn't care about your semantics, nor do they care what you studied. They use words colloquially. How much food did you eat today? 2000 calories? Did you mean kilocalories?

Heh. Regulations are more and more strict so that marketeers are not allowed to actually lie to gain profit.

And indeed calories do have a long standing history that they are actually kilocalories.
So I've just checked a food wrapping (Netherlands), and guess what, it does say kcal. After all, saying calories would be lying even though there is a history for it that might allow it. So now I'm wondering if we still have commercials or some such that promote a (low) specific number of calories... maybe if it's in casual language, but otherwise...

Selling a 512 GB magnetic hard drive as 512 GiB would be lying, so that will be disallowed.
To be honest, it's actually in their interest to sell a 512 GiB SSD as is, since that implies it is bigger than the 512 GB magnetic hard drive (and faster).
Then again, I expect them to sell 512 mb SSD's. ;/
I'd only want one if it had quantum bits.

 

[newjerseyrunner]

And indeed calories do have a long standing history that they are actually kilocalories.
So I've just checked a food wrapping (Netherlands), and guess what, it does say kcal. After all, saying calories would be lying even though there is a history for it that might allow it. So now I'm wondering if we still have commercials or some such that promote a (low) specific number of calories... maybe if it's in casual language, but otherwise...

Cereal, yogurt, sports drinks... all advertise how lean they are with calories. I've literally never heard the word kilo-calorie on tv.

iPhones are advertised as 64 gigabytes. They may use the correct capitalization on the box, but spoken advertisements absolutely say "gigabyte" not "gibibyte."

seagate always do the opposite, they say gigabyte and mean gigabyte: http://knowledge.seagate.com/articles/en_US/FAQ/172191en

 

[I like Serena]

Cereal, yogurt, sports drinks... all advertise how lean they are with calories. I've literally never heard the word kilo-calorie on tv.

'Lean on calories' is correct, whether they be calories or kilocalories.
Saying they have less than 10 calories, when they mean less than 10 kilocalories, would be wrong.

iPhones are advertised as 64 gigabytes. They may use the correct capitalization on the box, but spoken advertisements absolutely say "gigabyte" not "gibibyte."

'Spoken on TV' presumably counts as casual, which may allow it, and which may depend on which country we live in.
Showing it on the box would be more serious. I don't think they can get away with it that they didn't know any better.

seagate always do the opposite, they say gigabyte and mean gigabyte: http://knowledge.seagate.com/articles/en_US/FAQ/172191en

So Seagate sells a hard drive as 500 GB (real giga bytes), which Windows reports as 465 GB (really gibibytes).
Seagate does here what legislation requires, and what actually looks good in marketing, although the fact that they have to explain the difference comes back to bite them.
And Windows is off here with its unit. Is that before or after the standardization?
Still, it makes sense for an operating system to report disk space in GiB.
That's because the OS tends to map the locations on hard disk space to memory, which requires powers of 2. But that does not apply to a hardware manufacturer.
Anyway, at least the Mac reports the space properly.

 

[newjerseyrunner]

'Lean on calories' is correct, whether they be calories or kilocalories.
Saying they have less than 10 calories, when they mean less than 10 kilocalories, would be wrong.

It’s not wrong, it’s just colloquial. And they do specific amounts in calories. Miller 64 has 64 calories, Pepsi One has one calorie, 5 hour energy has “under four calories.” All Of which mean kilocalories.

I think computers are going through the same colloquialism. In fact, I’m casual conversation who even says gigabytes or gibibytes? It’s just plain “gigs.”

 

[cjl]

seagate always do the opposite, they say gigabyte and mean gigabyte: http://knowledge.seagate.com/articles/en_US/FAQ/172191en

That's pretty standard in storage - even SSDs use the same convention at this point. For example, note that Samsung's 1TB SSD is shown as 1000GB, not 1024:
https://www.samsung.com/us/computin...ives/ssd-850-evo-msata-1tb-mz-m5e1t0bw/#specs

In general, I'd assume that storage is using base 10, but memory (RAM) is using base 2, unless otherwise specified.