How come if I buy a 4gb memory stick pro duo for my psp the memory is 3904 but it should be 4000?

Question

How come if I buy a 4gb memory stick pro duo for my psp the memory is 3904 but it should be 4000?

Answer 1

There are some files and data the manufactures have to install into the memory tick.  For example, they need to program the memory stick with items that format into the psp.

Answer 2

it is the convention standard used

1 Gig = 1024MB (true)

or

1 Gig= 1000MB (close to true)

Answer 3

There is room for confusion indeed if a manufacturer announces 4000 Mb of memory and you get only 3904 Mb which you can use. I also felt cheated when I saw this.

But it is just the way these things go. It is easier to round off the number of the memory stick's capacity and say, for example, that there is a 4 GB memory stick, rather that stating "3904 Mb available capacity", partly because that is not quite correct.

The stick indeed has 4000 MB of memory space on it, but as it is a digital add-on device, it needs to connect to another device in order to be put to use. The PSP, which is a mini computer, will need to recognize the Pro Duo stick as an external hard drive. For both devices to be able to communicate with each other, various software protocols are needed and some of that software has to be present on the memory stick, otherwise, the PSP wouldn't be able to recognize it.

That's where the missing megabytes are: they have been used up so the devices can talk to one another. The consolation prize is that your memory stick indeed has the announced capacity, so actually, you have not been cheated, but thrown into unnecessary confusion.