46 ms·

> 2^10 = 1024 (1 KB) 1000 2^10B = 1024B = 1KB ~ 1kB = 1000B as I understand it. And for MB or Mb the accuracy is not really interesting. Edit: It shoul

by jonsen 6y ago

> 2^10 = 1024 ~~ (1 KB) ~~ 1000 2^10B = 1024B = 1KB ~ 1kB = 1000B as I understand it. And for MB or Mb the accuracy is not really interesting. Edit: It should in fact be 1kB ~ 1000B E.g. 1kg is not exactly 1000g, that would be 1.000kg. But 1KB is meant to be exactly 1024B.

dghf 6y ago
> 1kg is not exactly 1000g, that would be 1.000kg Really? Why? I would have assumed that 1kg is in fact exactly 1000g, and that the trailing zeros in 1.000kg indicated a rounding to three decimal places: i.e. 999.5g <= 1.000kg < 1000.5g
- jonsen 6y ago
  I may have used ‘exactly’ sloppy here. What I mean is: When the context doesn’t say otherwise, one should assume accuracy or precision as rounding to the least significant digit given. I.e. by default 1kg may indicate a mass between 500g and 1.499g. If the accuracy is about 10g you should write 1.00kg.
mjevans 6y ago
Base 10 Engineering Notation uses SI Prefixes, for these a set of letters exist with the upper-case indicating positive exponents (large numbers) and lower-case indicating negative exponents (small parts of one unit) https://en.wikipedia.org/wiki/International_System_of_Units#Prefixes https://en.wikipedia.org/wiki/International_System_of_Units#... Offhand, and at a glance, none of the upper case correspond to a lower-case prefix. This is probably to detect incorrect usage. In Computer Science / programming generally, the convention has been that an uppercase B indicates bytes, while a lowercase indicates bits. Modern computing systems frequently address integer numbers of size 64b, 32b, 16b, 8b (8B, 4B, 2B, 1B respectively). Examples: 1 Gb (SI G bit, since if discussing bits telecom stuff is implied; I argue that this too is incorrect, but it's efemeral, not storage. Still I can't send less than a byte.) 1 GB (CS G Byte) storage somewhere, memory. Invariably a base 2 power since otherwise packing and transcription to accommodate re-packing would be a power-hungry nightmare.
- jonsen 6y ago
  > upper-case indicating positive exponents (large numbers) and lower-case indicating negative exponents The prefix kilo is lower case k. Hecto and deca are also lower case abbreviations.
- jonsen 6y ago
  It’s highly context dependent if 1GB means exactly 2^30 bytes or another number in the neighborhood of 1GB.

> 2^10 = 1024 ~~ (1 KB) ~~ 1000 2^10B = 1024B = 1KB ~ 1kB = 1000B as I understand it. And for MB or Mb the accuracy is not really interesting. Edit: It shoul

by jonsen 6y ago

dghf 6y ago

> 1kg is not exactly 1000g, that would be 1.000kg Really? Why? I would have assumed that 1kg is in fact exactly 1000g, and that the trailing zeros in 1.000kg indicated a rounding to three decimal places: i.e. 999.5g <= 1.000kg < 1000.5g

jonsen 6y ago
I may have used ‘exactly’ sloppy here. What I mean is: When the context doesn’t say otherwise, one should assume accuracy or precision as rounding to the least significant digit given. I.e. by default 1kg may indicate a mass between 500g and 1.499g. If the accuracy is about 10g you should write 1.00kg.

mjevans 6y ago

Base 10 Engineering Notation uses SI Prefixes, for these a set of letters exist with the upper-case indicating positive exponents (large numbers) and lower-case indicating negative exponents (small parts of one unit) https://en.wikipedia.org/wiki/International_System_of_Units#Prefixes https://en.wikipedia.org/wiki/International_System_of_Units#... Offhand, and at a glance, none of the upper case correspond to a lower-case prefix. This is probably to detect incorrect usage. In Computer Science / programming generally, the convention has been that an uppercase B indicates bytes, while a lowercase indicates bits. Modern computing systems frequently address integer numbers of size 64b, 32b, 16b, 8b (8B, 4B, 2B, 1B respectively). Examples: 1 Gb (SI G bit, since if discussing bits telecom stuff is implied; I argue that this too is incorrect, but it's efemeral, not storage. Still I can't send less than a byte.) 1 GB (CS G Byte) storage somewhere, memory. Invariably a base 2 power since otherwise packing and transcription to accommodate re-packing would be a power-hungry nightmare.

jonsen 6y ago
> upper-case indicating positive exponents (large numbers) and lower-case indicating negative exponents The prefix kilo is lower case k. Hecto and deca are also lower case abbreviations.
jonsen 6y ago
It’s highly context dependent if 1GB means exactly 2^30 bytes or another number in the neighborhood of 1GB.