It might be because he is not using nintendo's sdk anymore, particularly the "microcode" for RSP "coprocessor". Most N64 emulators usually do not emulate RSP properly, but detect which specific nintendo's microcode is used and then emulate it's behavior.

At the end of the video he says it needs real hardware or a "highly accurate emulator like Ares".

Does anyone know what it means for something to be a "multi-core emulator" like Ares is? Like, is there some underlying benefit to developing emulators for multiple systems under the same name? Is there some shared code or what?

That means they are not accurate cores since it works fine on real hardware.

Correct, both of them are really really old, accuracy wise. N64 emulation has improved a lot in the past 4-5 years, but old emulators haven’t caught up

N64 is (still) poorly understood.

Traditionally, emulators relied heavily on HLE. Low-level efforts are recent and not mature.

The miSTer core for N64 (and ModRetro's M64 core effort by the same person) and Ares N64 support are the only two serious efforts I am aware of. They tend to share compatibility issues, and advance together when understanding of the platform grows.

(I maintain the Ares N64 core)

Obviously this is just a personal judgment, but I believe N64 is currently understood at quite a good level. Most of the docs are on https://n64brew.dev/. Low level efforts are recent for sure, though I'm not sure I would rate them as "not mature". Ares is able to run most of the library (including 64DD) and all the homebrew library with zero per-game configurations or tweaks.

The standards I applied are not some subjective "good level" but bsnes-level. The way Near intended.

The one game I am aware of and keep checking is "Wonder Project J2 - Koruro no Mori no Jozet".

Broken in both Ares and the miSTer core. AIUI nobody knows why it does not work yet, which shows gaps in the understanding of the machine. Otherwise not an issue for me, as I can run it on the actual hardware, which I own.

Note that, in no small way, I do appreciate the efforts. The state of the art of N64 emulation is much better now than just a few years ago. But it sure is not there yet.

I believe there's no way, on today's PC hardware, to emulate a 5th-gen console as accurate as a 4th-gen one. 4th-gen consoles can be emulated with cycle accuracy, 5th-gen cannot.

N64 also happens to be by far the heavier console to emulate in 5th-gen group. The unified memory architecture poses unique challenges for cycle accuracy, given that conflicting accesses by different peripherals are serialized in various ways, causing stalls, and also non deterministic behaviors as the signals cross different clock domains.

So the issue is in part that this level of detail hasn't been fully reverse engineered yet, but that's because there is no rush since the information wouldn't be usable anyway right now in an emulator.

5th gen definitely constitutes a huge jump in complexity. N64 is indeed not easy.

I am hopeful as ModRetro's m64 launches, with a FPGA larger than the one in the miSTer, and there's an associated influx of developers looking at the platform, we'll see renewed energy directed towards understanding the N64.

Don't use retroarch, his project lead is a terrible person who leeches off from donations without repassing to the core contributors that does the actual work.

Use decent emulators that are actually accurate.