zlacker

[return to "1 kilobyte is precisely 1000 bytes?"]
1. jachee+s8[view] [source] 2026-02-03 17:31:08
>>surpri+(OP)
The entire reason "storage vendors prefer" 1000-based kilobytes is so that they could misrepresent and over-market their storage capacities, getting that 24-bytes per-kb of expectation-vs-reality profit.

It's the same reason—for pure marketing purposes—that screens are measured diagonally.

◧◩
2. dr_zoi+W9[view] [source] 2026-02-03 17:36:27
>>jachee+s8
Not sure about that, SSDs historically have followed base-2 sizes (think of it as a legacy from their memory-based origins). What does happen in SSDs is that you have overprovisioned models that hide a few % of their total size, so instead of a 128GB SSD you get a 120GB one, with 8GB "hidden" from you that the SSD uses to handle wear leveling and garbage collection algorithms to keep it performing nicely for a longer period of time.
◧◩◪
3. quotem+9c[view] [source] 2026-02-03 17:44:20
>>dr_zoi+W9
Sounds like an urban legend. How likely is it that the optimal amount over-provisioning just so happens to match the gap between power-ten and power-two size conventions?
◧◩◪◨
4. nerdsn+Ke[view] [source] 2026-02-03 17:53:56
>>quotem+9c
It doesn't, there's no singular optimal amount of over-provisioning. And that would make no sense, you'd have 28% over-provisioning for a 100/128GB drive, vs 6% over-provisioning for a 500/512GB drive, vs. 1.2% over-provisioning for a 1000/1024GB drive.

It's easy to find some that are marketed as 500GB and have 500x10^9 bytes [0]. But all the NVMe's that I can find that are marketed as 512GB have 512x10^9 bytes[1], neither 500x10^9 bytes nor 2^39 bytes. I cannot find any that are labeled "1TB" and actually have 1 Tebibyte. Even "960GB" enterprise SSD's are measured in base-10 gigabytes[2].

0: https://download.semiconductor.samsung.com/resources/data-sh...

1: https://download.semiconductor.samsung.com/resources/data-sh...

2: https://image.semiconductor.samsung.com/resources/data-sheet...

(Why are these all Samsung? Because I couldn't find any other datasheets that explicitly call out how they define a GB/TB)

[go to top]