When 1 GB Is Really 0.9313 Gigabytes

An anonymous reader writes "When it comes to RAM, as every geek knows, 1 GB does not mean 1 billion bytes.. it means 2**30 (1,073,741,824) bytes. However, several decades ago "they" decided that GB, MB, and KB would be interpreted differently when it comes to disk drives; 1 GB means exactly 1 billion bytes. Ed Bott points out that Microsoft's marketers and Windows kernel developers aren't on the same page when it comes to these units: the marketers use the more generous decimal interpretation, while Windows measures and reports capacity using the binary (2**30) measure. Careful customers who bother to check what they've got have been known to get peeved by the discrepancy."

Comments

Terabytes

[Janek Kozicki]

It gets worse when you start counting terabytes. I recently bought a 2TB HDD and grown my mdadm raid array using:

mdadm --add /dev/md69 /dev/sde3
mdadm --grow --bitmap=none /dev/md69
mdadm --grow --raid-devices=5 --backup-file=/root/grow_md69.bak /dev/md69
mdadm --grow --bitmap=internal --bitmap-chunk=65536 /dev/md69
resize2fs /dev/md69

And I was surprised that my filesystem grew only by 1800 GB ! Still a bit more space for rsnapshot cron backing up all my family's PCs twice per day. But still... I wanted 2TB more, not 1.8TB.

GiB

[Anonymous Coward]

Finally adopt the official prefixes.
If you are talking decimal, use GB. If you are talking binary, use GiB.

Re:GiB

[phluid61]

"official" on whose auth ?

The IEC. International Electrotechnical Commission (January 1999), IEC 60027-2 Amendment 2: Letter symbols to be used in electrical technology - Part 2: Telecommunications and electronics. * http://physics.nist.gov/cuu/Units/binary.html

Re:"they" can fuck off, the binary units are the o

[dingen]

Actually, when it comes to correctness: the International System of Units defines kilo-, mega- and giga- as powers of 10 instead, not powers of 2. I think it is much clearer for a user to define a megabyte as a million bytes. How memory is handled inside a computer is something developers care about, no user should be bothered with it. So all in all I agree with the marketing-people, albeit for different reasons.

Re:"they" can fuck off, the binary units are the o

[gomiam]

I don't know about hearing, but I have read GiB and MiB at the Linux kernel logs since quite a long time.

Re:Blame the marketers - WRONG?

[StoneyMahoney]

I call tentatively BS on this explanation:

https://en.wikipedia.org/wiki/Timeline_of_binary_prefixes

While far from definitive, this would seem to suggest that the first reference equivocating 1k with 1024 with an article in 1964 by Gene Amdahl, followed by a similar assumption of equivalence in a 1965 article by MV Wilkes. I think it's safe to say these references pre-date those hard drives you mention.

This would suggest that computer science did originally adopt the standard definitions of kilo etc. but then started to deviate from them in the mid-60's for the sake of ease.

Re:"they" can fuck off, the binary units are the o

[synapse7]

So this site is now called ./? What happed to /.?

Re:What. The. Fuck?

[Bengie]

You are obviously not a computer engineer. You try to do memory allocations in increments of base 10. Anyone who understands computers know that it isn't just "annoying", it is something that doesn't work correctly. Forcing base 10 onto a computer that works in base 2 is a logical fallacy.

I know, lets use the floating point unit to address memory! /derp