SSDs are.
Comment on Why a kilobyte is 1000 and not 1024 bytes
wischi@programming.dev 5 months agoBinary prefixes (the ones with 1024 conversations) are used to simplify numbers that are exact powers of two - for example RAM and similar types of memory. Hard drive sizes are never exact powers of two. Disk storing bits don’t have anything to do with the size of the disk.
gens@programming.dev 5 months ago
wischi@programming.dev 5 months ago
Not even SSDs are. Do you have an SSD? You should lookup the exact drive size in bytes, it’s very likely not an exact power of two.
gens@programming.dev 5 months ago
Checked and true. 500107862016 bytes.
Still, ssds are made of n^2 chips.
wischi@programming.dev 5 months ago
I’m not sure if that’s your disk size or partition size but it’s not a power of two: www.wolframalpha.com/input?i=prime+factors+of+500…
The underlying chips certainly are exact powers of two but the drive size you get as a consumer is practically never an exact power of two, that’s why it doesn’t really make sense to divide by 1024.
The size you provided would be 500107862016 / 1024 / 1024 / 1024 = 465.76174163818359375 GiB
Dividend by 1000³ it would be 500.107862016 GB, so both numbers are not “pretty” and would’ve to be rounded. That’s why there is no benefit in using 1024 for storage devices, even SSDs.
The situation is a bit different with RAM. 16 “gig” modules are exactly 17179869184 bytes. www.wolframalpha.com/input?i=prime+factors+of+171…
So you could say 17.179869184 GB or 16 GiB. Note that those 16 GiB are not rounded and the exact number of bytes for that RAM module. So for memory like caches, RAM, etc. it definitely makes sense to use binary prefixes with 1024 conversation but for storage devices it wouldn’t make a difference because you’d have to round anyway.
meekah@lemmy.world 5 months ago
sure, but one of the intrinsic properties of binary data is that it is in binary sized chunks. you won’t find a hard drive that stores 1000 bits of data per chunk.
abhibeckert@lemmy.world 5 months ago
The “chunk” is often 32,768 bits these days and it never matches the actual size of the drive.
A 120 GB drive might actually be closer to 180 GB when it’s brand new (if it’s a good drive - cheap ones might be more like 130 GB)… and will get smaller as the drive wears out with normal use. I once had a HDD go from 500 GB down to about 50 GB before I stopped using it - it was a work computer and only used for email so 50 GB was when it actually started running out of space.
wischi@programming.dev 5 months ago
Look up the exact number of bytes and then explain to me what the benefits are of using 1024 conversations instead of 1000 for a hard drive?