When 1 GB Is Really 0.9313 Gigabytes 618
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."
Terabytes (Score:5, Informative)
mdadm --add /dev/md69 /dev/sde3 /dev/md69 /dev/md69 /dev/md69 /dev/md69
mdadm --grow --bitmap=none
mdadm --grow --raid-devices=5 --backup-file=/root/grow_md69.bak
mdadm --grow --bitmap=internal --bitmap-chunk=65536
resize2fs
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 (Score:5, Informative)
Finally adopt the official prefixes.
If you are talking decimal, use GB. If you are talking binary, use GiB.
Re:GiB (Score:4, Informative)
"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 [nist.gov]
Re:"they" can fuck off, the binary units are the o (Score:5, Informative)
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 (Score:5, Informative)
Re:Blame the marketers - WRONG? (Score:5, Informative)
I call tentatively BS on this explanation:
https://en.wikipedia.org/wiki/Timeline_of_binary_prefixes [wikipedia.org]
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 (Score:4, Informative)
Re:What. The. Fuck? (Score:4, Informative)
I know, lets use the floating point unit to address memory!