Nemotron 3 Diarization

Who spoke when, in 107 megabytes. Nemotron 3 Diarization is NVIDIA’s open speaker-diarization model: a 100M-parameter Sortformer descendant that decides which of up to eight speakers is talking, in real time, and ranks #1 on VoiceArena’s Diarization-Bench leaderboard at a 14.72% Diarization Error Rate. Against NVIDIA’s previous four-speaker streaming baseline it cuts DER by an average of 41% relative at 1.04-second latency, with the advantage widening as speaker counts rise - the eight-speaker support is what makes it a meetings model rather than a phone-call model.

Streaming and offline in one checkpoint. One checkpoint covers both modes: input buffer as low as 80ms for latency-critical uses (the recommended floor is 0.32s), 30.4s buffer for offline-quality transcripts, output frames in 10ms multiples, and chunked inference with no duration limit. It produces speaker activity and timestamps, not words: chain it with a timestamped ASR model (Nemotron ASR 3.5 or Parakeet TDT 0.6B v3) and word-to-speaker mapping gives you attributed transcripts, the piece every local meeting-assistant pipeline was missing.

What runs where. Two routes. The NeMo path wants Linux with an NVIDIA Ampere-or-newer GPU. The interesting one for this audience is NeMo-Speech.cpp, NVIDIA’s C++ runtime (nemo-speech diarize meeting.wav, or --diarize to tag a transcript with word-level speakers), plus community ports: a GGUF at 198.7 MB bf16 / 106.7 MB q8_0, ONNX, CoreML, and LiteRT builds, which put real-time diarization on CPUs and phones, not just CUDA boxes. License is openmdw-1.1, explicitly ready for commercial use, which is the difference between a demo and a pipeline component. 26,000 downloads in five days say the meeting-tools crowd noticed.