Yeah don't bother, nsx2 won't run any games and if it manages to, performance will be much worse than PCSX2.
Use PCSX2 instead, slow speeds will exist with any PS2 emulator at this time. Even beefy high tech machines will have trouble emulating games at a playable or acceptable speed on PCSX2 which is the fastest and most compatible PS2 emulator out there right now.
Basically the other PS2 emulators are figuratively speaking *dead* and haven't received updates for a good while now.