# TITAN-MoE research log (WP33 UQO) Chronological, append-only. Times are local (America/Toronto). Every entry names the artifact it produced. ## 2026-11-01 — Session 1: mandate received, Gate A started - 13:xx Mandate pasted by the author (verbatim copy in `docs/MANDATE.md`). Project placed in the UQO working-paper series as **WP33**, directory `Recherche-UQO/ia/titan-moe/` (series convention; the mandate's `wp33_titan_moe/` name is kept as the repository name `wp33_uqo.git` on spbgit — see DECISIONS D-001). - Scaffold created from `_modele-working-paper` (UQO LaTeX template, Makefile, .latexmkrc, title pages). Git repo initialised (`main`). - Python 3.12 venv (`uv`): mlx 0.32.4, mlx-lm 0.32.2, numpy 2.5.4 (laptop). Lock file to be written at Gate B. - Reference repositories shallow-cloned into `third_party/` (git-ignored) with commit hashes recorded in `research/prior_art.csv`: colibri `0a5504a` (2026-10-31), mlx-lm `736ab0d` (2026-10-30), mlx `bd63d38` (2026-11-01, version header 0.32.5), llama.cpp `a91eab6` (2026-10-31). - Hardware inventory of the MacLustr LAN launched (29 aliases). Results in `artifacts/environment.json` (sanitized) and `artifacts/private/inventory-2026-11-01.txt` (not committed). 7 aliases unreachable at probe time (SSH timeout): M2M32, M2M32b, M4M36, m4ma, m4mb, m4mc, m2m16; M4BP48 answered with an empty record. Treated as unavailable for WP33 unless they come back; not assumed from historical notes. - Literature search delegated to a web-research sub-agent (output → `research/RELATED_WORK.md`, `research/prior_art.csv`, `paper/references.bib`), to be verified entry by entry before use. - Small open-licensed MoE chosen for Gate B: `mlx-community/OLMoE-1B-7B-0125-Instruct-4bit` (Apache-2.0, 3.9 GB, revision `e2384419`), download started 2026-11-01 (laptop HF cache). - OLMoE-1B-7B-0125-Instruct-4bit downloaded (33 s). Layout read from `model.safetensors` (`benchmarks/raw/gateA/smoke/`): per-expert tensors `model.layers.L.mlp.experts.E.{gate,up,down}_proj.{weight,scales,biases}` (affine 4-bit, group 64; gate/up weight U32 [1024,256] = 1.05 MB + scales/biases F16 2×64 KB; down [2048,128] = 1.05 MB + 2×64 KB) → **3.375 MiB per expert**, 1 024 experts = 3.625 GB; attention 0.151 GB; embeddings/head 0.116 GB (tied). Per decode token: 16 layers × top-8 = 128 experts = 432 MiB of weights touched. - Smoke baseline mlx-lm `generate` on the laptop (M5 Max, 48 GB, mlx 0.32.4, mlx-lm 0.32.2, temp 0, 33-token prompt, 85 generated): prompt 45.0 tok/s (includes first-call compilation), generation **493.9 tok/s**, peak memory 4.11 GB. Raw: `benchmarks/raw/gateA/smoke/mlx_lm_generate_laptop_*.txt`. - SSD probe `benchmarks/scripts/ssd_bandwidth.py` (single-threaded `pread`, F_NOCACHE after `sudo purge`): laptop random 3.4 MB reads **8.50 GB/s** (p50 0.43 ms / chunk, p99 0.49 ms), page-cached 28.4 GB/s, sequential 8 MB reads 11.5 GB/s. Lesson: F_NOCACHE alone does not evict already-cached pages — `purge` is mandatory before a cold measurement (first attempt read 37 GB/s = cache). Raw: `benchmarks/raw/gateA/ssd/laptop-M5Max.json`. - Design microbenchmark for the slot table (`benchmarks/raw/gateB/design/slot_update_microbench_laptop.txt`): in-place slot update 0.305 ms; gather_qmm 0.260 ms/layer; per-expert loop 0.428 ms; restack 0.502 ms; lazy mmap expert load 0.53 ms (cached). - **Gate B implemented**: `titan/registry.py` (safetensors byte ranges, routing semantics), `titan/store.py` (pread SSD tier with accounting), `titan/slots.py` (LRU/LFU slot tables, stall accounting), `titan/moe.py` (TitanSwitchGLU, exact row chunking), `titan/runtime.py` (mlx-lm host model with experts spliced out). Tests `tests/` (7 passed, raw `benchmarks/raw/tests/pytest_gateB_20261101T011805.txt`): registry; pread bytes == `mx.load` bytes; logits vs mlx-lm **max |Δ| = 0.0** for capacity 64/32/16/8 on 4 prompts (argmax equal); greedy 32-token decode token-identical with 16 slots. First unfused activation attempt gave Δ = 0.0195 (fixed, D-006). - Literature pass completed: 59 verified works → `research/prior_art.csv`, `paper/references.bib` (59 entries), synthesis and novelty matrix in `research/RELATED_WORK.md`.