Petabajt je 10^15 B - podle standardu SI.
Pocitace pracuji v dvojkove soustave, ale lidi pracuji v desitkove a vetsinou preferuji zobrazeni udaju v desitkove soustave.
Lepsi je precist si "na disku je 710934528 bajtu volneho mista" ve desitkove soustave nez "na disku je 101010011000000000000000000000 bajtu volneho mista" ve dvojkove.
A 2^50 B je pebibyte. Bohuzel, lidi casto pebibyte chybne oznacuji jako petabyte.
http://en.wikipedia.org/wiki/Binary_prefix
"Current national and international standards state that traditional SI prefixes always refer to powers of ten, even in the context of information technology"