psp 128gb via 1 mirco sd hc + single adapter

[[Unknown]]

Well, that's because the industry uses SI units of measure. It's a crock really.

A 128GB storage card is 128 billion bytes (gigabytes) of space. However, all software measures space based on a power of 2, that is "gibibytes" technically. These are not SI units, and are multiplied by 1024 (which is a power of 2) rather than 1000 (which is a power of 10.)

24 bytes seems like an awfully small difference, but it adds up.

128 * 1024 * 1024 * 1024 - 128 * 1000 * 1000 * 1000

The difference is 9438953472 total bytes, or in other words just under 9 gibibytes. Or else just over 9438 SI GB.

So, you should theoretically only have 119 GB ("GiB" technically) of usable space with a 128 GB card. This applies even to Sony Memory Stick Pro Duo cards. Pretty much all storage is marketed based on the more advantageous measure of SI units.

-[Unknown]