A lot of people here are spreading misinformation. As someone who has SX Core, let me tell you that you can emulate all of these systems. For DS, use the MelonDS standalone emulator and disable "Fast emulation". That will let you run DS games pretty flawlessly. Fast emulation crashes on SX OS though. For all the others use retroarch. For N64 use Mupen64-Next, for PSP use PPSSPP (never tried this one myself), and for 3DS, you will have to join M4XW's patreon and grab the Citra core from the RetroNX discord. IF YOU SEEK SUPPORT IN RETRONX DO NOT SAY YOU ARE USING SX OS. M4xw does not take kindly to that and will instantly ban you (speaking from experience). You can use Tesla overlay and sys-clk to overclock your system on the fly. People will also tell you you can't do this on SX OS, but all you have to do is rename the atmosphere folder to "sxos" and the "contents" folder to "titles"