tech.engineering.computer.numbers
Created Wednesday 01 October 2025
Why is it sometimes 1000 and sometimes 1024?
A MB was 1024 KBs up until 1999 when the IEC invented MiB to denote being 1024 based and changed MB to being SI 1000 based [1][2][3]. Microsoft Windows uses the old pre-1999 standard [6]. Drive makers use the new standard, allowing them to lie with marketing and sell less as more [1][4]. Linux utilities seem to use the new IEC standard by default (atleast gnu df) [7].
It's chaos. I remember the RHCSA exam is happy if you just get close to any target size.
References
1 https://www.reddit.com/r/pcmasterrace/comments/w9riwr/when_did_we_change_the_math/
2 https://forbrains.co.uk/standards/si_and_data_size_units
3 https://physics.nist.gov/cuu/Units/binary.html
4 https://xkcd.com/394/
5 https://www.explainxkcd.com/wiki/index.php/394:_Kilobyte
6 https://www.reddit.com/r/techsupport/comments/1erofcd/just_learned_that_windows_labels_storage_space_as/
7 https://www.gnu.org/software/coreutils/manual/html_node/df-invocation.html#df-invocation
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