Eh oui, il y a une différence entre les prefixes de la base 10 et les préfixes de la base 2: un kilo -> 10^3 (1000) != Ki -> 2^10(1024)
C'est un beau lobi des vendeurs (de disques durs): exemple en hd de 40 Go = 40 * 10^9 octets et non 40 * 2^30 ! Soit un manque de 2.949.672.960 octets Bref, on ne perd que 737.418.240 de bytes par Giga (7,37%!) Et comme le marché à tjrs raison, je ne pense pas que le HD s'acheteront un jour au gibi... En attentant les disques d'un exabinary bytes (Où la perte sera de 15,29%) voici les prefixes: kilobinary kibi- Ki 2^10 megabinary mebi- Mi 2^20 gigabinary gibi- Gi 2^30 terabinary tebi- Ti 2^40 petabinary pebi- Pi 2^50 exabinary exbi- Ei 2^60 Le Mercredi 28 Avril 2004 15:58, Alain EMPAIN a écrit : > Découvert en cherchant la valeur de lbs en kg: > > man units > > (...) > Prefix Name Value > Ki kibi 2^10 = 1024 > Mi mebi 2^20 = 1048576 > Gi gibi 2^30 = 1073741824 > Ti tebi 2^40 = 1099511627776 > Pi pebi 2^50 = 1125899906842624 > Ei exbi 2^60 = 1152921504606846976 > > Before these binary prefixes were introduced, it was fairly > common to use k=1000 and K=1024, just like b=bit, B=byte. > > Unfortunately, the M is capital already, and cannot be capitalized to > indicate binary-ness. > > At first that didn't matter too much, since memory modules and disks > came in sizes that were powers of two, so everyone knew that in such > contexts "kilobyte" and "megabyte" meant 1024 and 1048576 bytes, > respectively. > What originally was a sloppy use of the prefixes "kilo" and "mega" > started to become regarded as the "real true meaning" when computers > were involved. > > But then disk technology changed, and disk sizes became arbitrary > numbers. After a period of uncertainty all disk manufacturers > settled on the standard, namely k=1000, M=1000k, G=1000M. > > The situation was messy: in the 14k4 modems, k=1000; in the 1.44MB > diskettes, M=1024000; etc. > > In 1998 the IEC approved the standard that defines the binary > prefixes given above, enabling people to be precise and unambiguous. > > Thus, today, MB = 1000000B and MiB = 1048576B. > > In the free software world programs are slowly being changed to > conform. When the Linux kernel boots and says > > hda: 120064896 sectors (61473 MB) w/2048KiB Cache > > the MB are megabytes and the KiB are kibibytes. > > ------------------------- > On apprend tous les jours ;-) > > Alain -- ---------------------------------------------------- Rudi Jocqueau [EMAIL PROTECTED] IRC GROUP s.a. http://www.irc-group.be Responsable Marketing - Communication ---------------------------------------------------- _______________________________________________________ Linux Mailing List - http://www.unixtech.be Subscribe/Unsubscribe: http://www.unixtech.be/mailman/listinfo/linux Archives: http://www.mail-archive.com/[EMAIL PROTECTED] IRC: chat.unixtech.be:6667 - #unixtech
