How big is a 128-bit number? Using the prefix for the largest number we have (2^100), it can hold 268435456 quettabytes. There's no set SI prefix name for the 262144 (something)bytes that it is the equivalent of. 2^110 and 2^120 have no SI prefixes.
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Jim Fuller
in reply to daniel:// stenberg:// • • •Embedded hacking contest #2, decoded
daniel.haxx.seMahdi BM
in reply to daniel:// stenberg:// • • •for quickly getting a sense of how big 2^Y is, I usually like to calculate Z = 0.3 x Y and round it down. 2^Y is approximately equal to 10^Z.
For 2^128, it'll be 128*3/10 ~= 38 when rounded down. So 2^128 ~= 10^38.
In comparison, 2^64 ~= 10^19.
Simple logarithm trick. Log base 10 of 2 is ~= 0.30103 ~= 0.3.
chewey
in reply to daniel:// stenberg:// • • •"quetta" is NOT an SI prefix for 2¹⁰⁰, but for 10³⁰. For 2¹⁰⁰, the prefix is quebi.
Please don't mix those, that leads to values being quite off at the scale of "giga" already, and it's HILARIOUSLY off at the scale of 10³⁰.
/end of pedantry
aspragg
in reply to daniel:// stenberg:// • • •We could start using systematic binary prefixes, akin to systematic element names, for those that don’t already have an officially assigned name?
en.m.wikipedia.org/wiki/System…
So 2^128 bytes
= 2^8 x 2^120 bytes
= 256 x 1024^12 bytes
= 256 unbi-bibytes (12 = un bi)
Seems quite compact actually.
And could also extend to systematic SI prefixes for power-of-1000 magnitude numbers?
#units #siprefix
temporary name assigned to newly synthesized or not yet synthesized chemical elements
Contributors to Wikimedia projects (Wikimedia Foundation, Inc.)Andreas Scherbaum
in reply to daniel:// stenberg:// • • •