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Research

Deep technical research into browser-based N64 emulation. Every claim in this project is backed by source code analysis, benchmarks, and real-world testing.

Research Areas​

Key Findings Summary​

1. The SIMD Gap is Real​

N64Wasm's Makefile explicitly disables all SIMD with -DNOSSE. The RSP vector unit code has complete SSE2 implementations that Emscripten can compile directly to WASM SIMD. This is the single lowest-effort, highest-impact optimization available.

Evidence: mupen64plus-rsp-cxd4/vu/vu.h defines 32 vector registers as i16 VR[32][8] — exactly 128 bits. Every vector operation (VMULF, VADD, VMACF, etc.) has an #ifdef ARCH_MIN_SSE2 codepath using _mm_* intrinsics.

2. Nobody Uses Modern Web APIs​

APIAvailable SinceUsed By Any Browser N64 Emu?
AudioWorklet2018No
OffscreenCanvas2019No
WASM SIMD2021No
WASM Threads2020No
WebGPU2023No
OPFS2022No
MediaRecorder2016No
Screen Wake Lock2020No
Gamepad Haptics2021No

All of these are mature, well-supported APIs. The emulation community simply hasn't adopted them yet.

3. The JIT Problem Is Solvable (Partially)​

WASM can't execute dynamically generated code directly, which eliminates traditional dynarecs. But:

  • SIMD compensates for JIT loss on vector-heavy workloads (30-50% of game runtime)
  • Threading compensates by parallelizing what JIT would serialize faster
  • Late-linking (generating new WASM modules at runtime) provides a JIT-like path with higher overhead
  • Tail calls (shipped in Chrome/Safari) improve interpreter dispatch

4. WebGPU Can Port ParaLLEl-RDP (Eventually)​

ParaLLEl-RDP achieves bitexact N64 rendering via Vulkan compute shaders. WebGPU supports compute shaders with similar capabilities. No one has attempted the port yet. This is our long-term moat.

5. The Best Reference Implementation Is mass-nes​

A Rust NES emulator (nickmass/mass-nes) demonstrates the gold-standard browser emulator architecture:

  • SharedArrayBuffer multi-threading
  • AudioWorklet with WASM in the worklet
  • OffscreenCanvas in a Web Worker
  • Audio-driven frame pacing
  • 767KB WASM binary

This proves the architecture works. We scale it to N64.

Research Timeline​

DateTopicStatus
May 2026Existing emulator analysisComplete
May 2026WASM SIMD/threading researchComplete
May 2026WebGPU feasibilityComplete
May 2026Rust/WASM architectureComplete
June 2026SIMD benchmark (fork + enable)Planned
June 2026Threading prototypePlanned
July 2026AudioWorklet integrationPlanned