A question to the developers here: What is the expected read/write speed for the internal 3DS SD card? I'm testing with a small program (3DSX, running via Ninjhax, on N3DS) I wrote myself and have CTRUlib and CTRcommon installed, if that matters. And, it is much too slow. I've read somewhere that O3DS read / write speeds are equivalent to a class 4 SD. That would mean a write speed of 4Mbit / sec, which would be somewhat slow, but still acceptable. However, reading should be quite fast, because otherwise reading installed CIAs of sizes 1GB and above would take ages. And, related question, what (C/C++ standard) functions would you suggest to use to copy a file from SD to SD?