1 megabyte = how many bytes?

[Guybrush]

ok stupid question, but here's the deal:

1024k = 1 kilobyte, because it's 2 raised to the 10, but what is 1 megabyte? Is it 1000 kilobytes or 1024 kilobytes? I think it's 1000 but my roommate, who's doing his PhD in CS (guess they don't teach him anything) thinks it's 1000.

 

[rbayer]

Probably doesn't belong in Highly Technical, but here goes:

The size of a Megabyte (and a kilobyte, for that matter) really depends on who you ask. If you ask a HD manufacturer, it's 1000 bytes/kb and 1000 kb/mb. Ask an OS or a disk utility, and the answer is 1024bytes/kb and 1024 kb/mb. Same applies to the relation between MBs and GBs.

 

[chanfo]

Originally posted by: Guybrush
ok stupid question, but here's the deal:

1024k = 1 kilobyte, because it's 2 raised to the 10, but what is 1 megabyte? Is it 1000 kilobytes or 1024 kilobytes? I think it's 1000 but my roommate, who's doing his PhD in CS (guess they don't teach him anything) thinks it's 1000.

PhD in CS and he gets this wrong

 

[Guybrush]

doh, i meant my roommate thinks it's 1024. THanks

 

[Howard]

Originally posted by: Guybrush
doh, i meant my roommate thinks it's 1024. THanks

1024 bytes in a kilobyte
1048576 bytes or 1024 kilobytes in a megabyte
1073741824 bytes or 1048576 kilobytes or 1024 megabytes in a gigabyte

 

[ReiAyanami]

the SI prefix kilo means one thousand, therefore kilobyte equals 1000 bytes where a byte is 8 bits so

1kb = 8000 kilobits

the only reason why its all screwy today is that way back, ol billy gates decided it'd be funny to make up his own definition in computer standards against logical already established international standards

 

[dejitaru]

the only reason why its all screwy today is that way back, ol billy gates decided it'd be funny to make up his own definition in computer standards against logical already established international standards

Bill Gates didn't invent the digital computer (or much of anything).

I think it's 1000 but my roommate, who's doing his PhD in CS (guess they don't teach him anything) thinks it's 1000.

You two think the same, yet are arguing?

Basically, what Howard and rbayer said.

 

[Mark R]

The official definition as stated by the SI (System internationale), NIST (National Institutue for Science and Technology) and IEEE (Institute of Electrical and Electronics Engineers) is:

1 Megabyte = 1,000,000 bytes

Similarly:

1 kilobyte = 1,000 bytes
and
1 gigabyte = 1,000,000,000 bytes

Numerous parties have used unofficial definitions of megabyte - most commonly defined as 1,048,576 bytes, but I've seen 1,024,000 bytes as well.
Back when storage space was measured in kB, it didn't really matter much whether you used 1024 or 1000 - a difference of 2% was not regarded as particularly significant. It's use therefore became established. Now with storage space measured in GB the difference is 7%, and with TB will be 10%.

There are different prefixes for the binary based numbers although many organisations have been slow to adopt them, e.g: 1,048,576 = 1 MeB (mebibyte).

 

[Sunner]

There are actually two sets of units these days.

You have the kilo/mega/giga/tera/etc-byte.

And you have the kibi/mebi/gebi/tebi/etc-bytes.

According to SI:
1 Kilobyte = 1.000 bytes
1 kibibyte = 1.024 bytes

1 Megabyte = 1.000.000 bytes
1 Mebibyte 1.048.576 bytes

And so forth.

Personally I don't give a crap what SI says, neither does anyone else I know.
I work with UNIX systems all day long, and to me 1 Megabyte = 1.024 Kilobytes, 1 Kilobyte = 1.024 bytes, that's the way it's been for a long time, and it works fine enough for me, and obviously fine enough for lots and lots of other people too.

So, as several people have said, it depends on who you ask.

 

[juiio]

Kilobyte = 2^10
Megabyte = 2^20
Gigabyte = 2^30
etc

 

[RaynorWolfcastle]

Originally posted by: Sunner
There are actually two sets of units these days.

You have the kilo/mega/giga/tera/etc-byte.

And you have the kibi/mebi/gebi/tebi/etc-bytes.

According to SI:
1 Kilobyte = 1.000 bytes
1 kibibyte = 1.024 bytes

1 Megabyte = 1.000.000 bytes
1 Mebibyte 1.048.576 bytes

And so forth.

Personally I don't give a crap what SI says, neither does anyone else I know.
I work with UNIX systems all day long, and to me 1 Megabyte = 1.024 Kilobytes, 1 Kilobyte = 1.024 bytes, that's the way it's been for a long time, and it works fine enough for me, and obviously fine enough for lots and lots of other people too.

So, as several people have said, it depends on who you ask.

Regardless of what Unix programmers thought when they wrote up the OS, kilo is a prefix that means 1000, not 2^10. I think that hard drive manufacturers are absolutely right to say that a GB is 1,000,000 bytes. The OS people are the ones that decided to change the definition for their convenience and they are the ones to blame for the confusion. But obviously hard drive manufacturers are the ones that have to explain to Joe Consumer why his new 80 GB hard drive is missing a few GB so the point is moot and the whole discussion is academic.

 

[Sunner]

Originally posted by: RaynorWolfcastle

Originally posted by: Sunner
There are actually two sets of units these days.

You have the kilo/mega/giga/tera/etc-byte.

And you have the kibi/mebi/gebi/tebi/etc-bytes.

According to SI:
1 Kilobyte = 1.000 bytes
1 kibibyte = 1.024 bytes

1 Megabyte = 1.000.000 bytes
1 Mebibyte 1.048.576 bytes

And so forth.

Personally I don't give a crap what SI says, neither does anyone else I know.
I work with UNIX systems all day long, and to me 1 Megabyte = 1.024 Kilobytes, 1 Kilobyte = 1.024 bytes, that's the way it's been for a long time, and it works fine enough for me, and obviously fine enough for lots and lots of other people too.

So, as several people have said, it depends on who you ask.

Regardless of what Unix programmers thought when they wrote up the OS, kilo is a prefix that means 1000, not 2^10. I think that hard drive manufacturers are absolutely right to say that a GB is 1,000,000 bytes. The OS people are the ones that decided to change the definition for their convenience and they are the ones to blame for the confusion. But obviously hard drive manufacturers are the ones that have to explain to Joe Consumer why his new 80 GB hard drive is missing a few GB so the point is moot and the whole discussion is academic.

No need to explain the venefits of the metric system to me, Im from Sweden, so Im quite familiar with it.

What Im saying is, as far as software is concerneed, and this goes for *NIX, MS, and every OS I've ever used, 1 KB = 1.024 bytes.
That's enough for me, it works fine, the same way it's worked for roughly 3 decades, and until everyone agrees to call 1.024 Kilobytes 1 mebibyte I'll continue to not give a crap what SI says, and it's obvious enough many people feel the same.

 

[Afro000Dude]

Seems like the hard drive manufacturers could solve the problem by adding another 24 megabytes per *advertised* gigabyte. That way the people who want 1000 mb per gb are happy for the extra space, and Joe Consumer is happy that his 80G hard drive is actually 80G of usable space.

 

[dejitaru]

Seems like the hard drive manufacturers could solve the problem by adding another 24 megabytes per *advertised* gigabyte. That way the people who want 1000 mb per gb are happy for the extra space, and Joe Consumer is happy that his 80G hard drive is actually 80G of usable space.

You know them extra megabyes ain't free, buddy.

kilo==1024 only in a computer science context, but that's most probably what someone means when they say kilobyte.

We're actually arguing about this? Even I know that a kilometer is 1024 meters.

 

[Shalmanese]

Bah, when I'm programming, the maximum array size is 4 terabytes and the actual RAM I can use is 512MB. 2-prefix, not 10.

Personally, I think the 10 base i stupid in the context of computing. They should of named the numbers and there shouldnt even be a wrod called kilobyte.

EVERYTHING is measured in base 2 in computing.

 

[dejitaru]

OK, my posts are being truncated. Fatal bug.

 

[spidey07]

It totally depends on the industry and function.

In network world a kilobit is 1000 bits. A megabit is 1,000,000 bits, a gigabit is 1,000,000,000 bits.

Storage is a little different as discussed.

 

[Sunner]

Originally posted by: Shalmanese
Bah, when I'm programming, the maximum array size is 4 terabytes and the actual RAM I can use is 512MB. 2-prefix, not 10.

Personally, I think the 10 base i stupid in the context of computing. They should of named the numbers and there shouldnt even be a wrod called kilobyte.

EVERYTHING is measured in base 2 in computing.

I agree completely with this reasoning.

 

[bigshooter]

the only bad thing about using base 2 when determining kilobytes,megabytes, etc... is that we are using metric prefixes in a non metric way. metric was made to be easy, and its a lot easier for most people to add a 0 than to multiply a large number by two. although I use the base 2 definition of KB and MB every day, I think another name should be used liek the kibi, mebi, etc... If i started using 1024 instead of 1000 in my physics class, i don't think my instructor would give me credit for a correct answer.

BTW: can we argue about whether kb means just kilobits, and KB or Kb means just KiloBytes next? I always love those arguments when people says lower case means bit and uppercase means byte (although that is how I use it).