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2 Commits

Author SHA1 Message Date
jars
4cb954ece4 perf: route whisper + llm n_threads through physical-core helper
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Both inference call sites previously called `num_cpus::get()` (logical
thread count). Established whisper.cpp / llama.cpp guidance is that
SMT siblings contend for shared FPU resources during heavy F16/F32
matmul, so going past physical core count anti-scales. Empirical
sweep on Whisper Tiny / 11s JFK clip / Ryzen 5 4650U (6c12t):

  n_threads | xc_time | RTF    | speedup_vs_1
  ----------|---------|--------|-------------
          1 |   0.33s |  0.030 |   1.00x
          2 |   0.33s |  0.030 |   1.00x
          4 |   0.30s |  0.028 |   1.09x
          6 |   0.32s |  0.029 |   1.04x
          8 |   0.31s |  0.028 |   1.06x
         12 |   0.32s |  0.029 |   1.03x

Tiny doesn't scale (work dominated by overhead) but the larger
Whisper variants and Qwen LLMs do. Sources: whisper.cpp #200, #1033,
#1252, #403; llama.cpp #3167, #572.

Changes:
- crates/core/src/constants.rs:
  * MIN_INFERENCE_THREADS lowered 4 → 2 (research-derived floor)
  * MAX_INFERENCE_THREADS = 8 added (research-derived ceiling)
  * inference_thread_count() rewritten:
      - reads MAGNOTIA_INFERENCE_THREADS env var (override)
      - num_cpus::get_physical() with available_parallelism fallback
      - clamped to [MIN_INFERENCE_THREADS, MAX_INFERENCE_THREADS]
- crates/core/Cargo.toml: + num_cpus = "1"
- crates/transcription/src/whisper_rs_backend.rs: call site uses helper.
- crates/llm/src/lib.rs: call site uses helper.
- crates/transcription/Cargo.toml: drop num_cpus from [features] +
  [dependencies] (production no longer needs it). Move to
  [dev-dependencies] for tests/thread_sweep.rs only.
- crates/llm/Cargo.toml: drop num_cpus = "1" (no longer used directly).

Per-machine maps (after this patch):
  Ryzen 5 4650U  6c12t → 6
  big-iron 12c24t       → 8 (clamp; users can override)
  cheap 2c2t laptop     → 2
  1c container/VM       → 2

Adds crates/transcription/tests/thread_sweep.rs — env-gated like
jfk_bench, prints the table above against any model + WAV. Useful for
re-baselining on new hardware or when tuning the clamp values.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-09 09:26:23 +01:00
jake
6588130e36 feat(kon): add core crate — types, traits, hardware, model registry, recommendation
- Value objects: ModelId, EngineName, Megabytes, AudioSamples, Segment, Transcript
- KonError enum with thiserror
- Constants centralised: audio pipeline, VAD, RAM thresholds, inference threading
- SpeechToText and TextProcessor provider traits with ProviderRegistry
- Unified model registry (Whisper tiny/base/small/medium + Parakeet CTC int8)
- Hardware detection: probe_ram, probe_cpu, probe_gpu (stub), probe_os
- Recommendation engine: score_model (pure function), rank_recommendations (sorted)
- 5 tests passing, clippy clean

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-03-16 20:27:27 +00:00