Okay, computer geeks, what tells SD cards and other forms of data holders how much space they'll have?

[FunkyMonkee]

An SD card is just a tiny slip of metal embedded in a sheet of plastic. They go from a few MB up to a few dozen GB in amount of space they can hold but, what (or who) tells one slip of metal it can only hold a few MB and another the same size that it can hold 64 GB?

[NamerOfStars]

What *physically* determines the size is the number (and capacity) of memory modules on the chip; if you're looking for the exact mechanism that DISPLAYS capacity to the computer, I don't know; you'd need less a computer geek and more an engineer. It's almost certainly possible to spoof it, having it send a different (incorrect) signal, but that wouldn't actually give it more space; just make it CLAIM more.

It's the same thing that makes one hard drive have 200 gigs of space while another, of the same physical size, has only 400 megs.

[ArtemisSilver]

There's a file that tells your system the space on the device, it can be spoofed though, used to be a big problem on amazon where people were posting smaller drives as larger ones leading to data loss.

Physically it's a function of actual memory modules available.

Doing a full format on a drive will set the correct size, and they do break eventually.

[Astarlessnightsky]

There is a small file, like the first pages in a book, telling the pc/cam/phone/laptop/... what kind of media it is, how big it is, whats the manufactuerer...

[FunkyMonkee]

How does the computer know how big the card is if it's never touched it before and the card possibly didn't even exist before the computer was made?

[Astarlessnightsky]

Its written in the file

[Anonymous]

SSD and HDD have some intelligence and can tell you a bit about themselves. I presume flash cards are the same. The manufacturer imprints this information and the computer asks about it.

[FunkyMonkee]

Is there a way to bypass that so you can get a lot more space on it?

[Opinion Owner]

Sorry no. There is physically only so much space on these devices so even if you fooled the os, you still would run into problems actually storing stuff.
There are compression algorithms that may help depending on the type of data you are storing. Windows, for example, allows you to compress folders. I suspect most people go and get a bigger drive though.

[msc545]

The amount of storage is a function of how they are built and how many memory units are included in that build. You cannot change this.

[jshm2]

They have an interface controller.