Tester report (2× RTX 2080 Ti, Turing): #743 prompt A/B, #776 batch soak, #859 pipeline-windows, #848 resident soak — all pass #1143

Tested the four "Testers wanted" items on a dual-GPU Turing setup. All four pass — details below.

Environment

Each test ran on its own config file (production config untouched) and its own server process on :8080. Prompts were built with the repo's own tools/strata_tokenizer.py against the repo's docs corpus (round-trip re-encode drift = 0 tokens), sent non-streaming to /v1/chat/completions, greedy, reasoning_effort: none, and read back from the response's timings field.

1. #743 — Turing prompt test (wide top-k kernel) at 90K / 131K / 155K

STRATA_TOPK_STREAM read from the config's env block, set before engine start (fresh process per session, as required by the static const bool in qsa_select.cu). All three sizes sit above the 90,112-cell kernel boundary. Distinct corpus offsets per size + cache_n verified 0 on every single request (no prefix-cache interference).

• Re-run of 131,072 on the new kernel after the old-kernel session: 1,432.5 tok/s (−0.2 % vs first run) → no thermal/drift artifact; the ordering holds.
• Decode at 158,720 tokens: 61–64 tok/s, no anomalies, finish reason length as expected.
• Wall time for the full request (155K in + 32 out): 115 s.

Verdict: no regression on Turing; the new wide top-k kernel is equal or slightly faster at every length above the boundary.

2. #776 — --batch 4 on the all-resident layer-split config

• Config: production flags + --batch 4. Server reported concurrency: {serving: 4, requested: 4}; engine log confirms batch windows of up to 4 sequences on both stages.
• Workload: 52 rounds × 4 concurrent greedy requests (80-token prompt, max_tokens: 200) over ~8 minutes → 208 requests total.
• Result: 0 failures, engine never exited, server never unreachable, no loops (the --batch on a 100%-resident layer split: engine dies at "captured the batch window over slots 0,1" (zero-doorbell path?) #776 symptom did not reproduce on 0.1.40).
• Per-sequence decode: 24–57 tok/s; aggregate 102–221 tok/s per round. Prompt path: 91–100 tok/s.
• Observation worth noting: with 4 batch slots, expert-cache residency dropped from 89 % → 80 % (slots take cache); host RAM stayed ~60 GB. So the zero-doorbell/100 %-resident path is not what a --batch 4 run hits on 22 GB cards.

Verdict: #776 fix confirmed, stable on Turing.

3. #859 — --pipeline-windows with interleaved conversations

Engine accepted --pipeline-windows 2 (clamped from any larger value as documented):

strata serve: --pipeline-windows 2: two verifiers per stage, the stages overlap across windows (decode too; the GDN snapshots beside the window)

Tested both requested combinations, 4 conversations × 4 rounds round-robin interleaved = 16 interleaved pairs each (exceeds the "10 or more pairs" ask), prompts growing 72 → 147 tokens, 300-token completions:

Second verifier costs 284 MiB of CUDA0 expert cache when resident mode is off (per engine log). No prompt-path or decode anomalies in either combination.

Verdict: both combinations stable; no hangs, no crashes.

4. #848 — resident RAM mode soak (30 minutes, solo serving)

Config: production flags + --resident-experts. Engine log confirms the mode is live:

strata generate: resident RAM mode: 5.46 GiB of experts in RAM (page-locked), 12094 in the GPU cache; adaptive swaps exchange them with the GPU cache (no file reads)
strata serve: layer split: 87% of the experts resident, the prompt path's streamed ring 96 slots

Workload: 30 minutes, 176 requests — one growing conversation (4 short rounds) plus a 20K-token prompt every 5th request (30 of them) to force expert-set churn through the adaptive swaps.

Verdict: stable for the full 30-minute soak; adaptive swaps show no slowdown over time and no memory creep.

Summary

Happy to rerun with different flags, add STRATA_STAGE_TRIM=0 variants, or share the raw timing JSONs (all recorded under test-results/).