I bought a 128GB SanDisk Cruzer Glide USB flash drive. I ran Check Flash and found out it is actually 118GB. That is a shortfall of 10 gig, but it doesn’t appear to be one of those gross fakes. It seems to read and write okay. Is this “normal”? If not, why would SanDisk, which has a decent reputation, stiff customers on this.
Base-10 gigabytes versus base-2 gigabytes.
SanDisk sold you something which has a capacity close to 128 * 10[sup]9[/sup] bytes, or 128 base-10 gigabytes. That’s called measuring the capacity the marketing way. However, every OS on Earth measures storage capacity the useful way, in the base-2 fashion, which better models how computers actually use storage, where a gigabyte is 2[sup]30[/sup] bytes.
(128 * 10[sup]9[/sup])/(2[sup]30[/sup]) is approximately 119 base-2 gigabytes of raw capacity, by my math. subtract some for formatting overhead, without which the disk is useless for most people, and extra “useful” utilities, which can be deleted with no loss of functionality, and you get 118 base-2 gigabytes.
Technically, a base-2 gigabyte is called a gibibyte. That word is not in Firefox’s spell checker. Nobody uses it.
SanDisk isn’t doing anything sketchy. Or more accurately, they are, but so is every other manufacturer.
It is sold in gigabytes (GB) but your computer technically measures in gibibytes (GiB).