50 lines
2.7 KiB
Markdown
50 lines
2.7 KiB
Markdown
# EXP-SIMFID-Q30-LATENCY-EXPANSION: remaining Fixed/Trace × PD/P cases
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> Status: prepared for runtime-alignment preflight (2026-07-18). The already
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> completed Qwen3-30B-A3B Trace-PD surface is excluded from this card.
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## Question and fixed boundary
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Does the same graph-aligned Frontier configuration that selected the correct
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winner on Trace-PD also select the real vLLM winner when either the arrival/
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prefix state or the decode phase is removed? This is a selection test, not an
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SLO/capacity evaluation.
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| Case | Input / output | arrival and cache | Applicable objectives |
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|---|---|---|---|
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| Fixed-PD | 2048 / 128 | 129 uniform requests; `t'=t/TP`; prefix cache off | mean/p90 TTFT, TPOT, E2E |
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| Trace-P | exact held-out input, arrival, session and complete block-16 prefix relation / 1 | same TP-normalized 129-row trace; prefix cache on | mean/p90 TTFT, E2E; TPOT=N/A |
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| Fixed-P | 2048 / 1 | 129 uniform requests; `t'=t/TP`; prefix cache off | mean/p90 TTFT, E2E; TPOT=N/A |
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All cases use Qwen3-30B-A3B BF16, community vLLM 0.20.0, H20, `TP∈{1,2,4}`
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and `MNS∈{8,16,32,64}`, MBT=8192, chunked prefill, three fresh-server trials
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per cell. The fixed QPS is the Trace-PD base offered rate (`129/600` req/s per
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GPU), hence the global arrival rate is multiplied by TP. It makes throughput
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per GPU comparable without claiming that different TP values see identical
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cluster-level load.
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## Simulator and real contracts
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- Frontier uses commit `deadc4a…`, `piecewise`, the frozen CUDA-event profile
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for prefill/mixed batches and KERNEL_ONLY profile for captured pure decode.
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- Trace-P reuses the already verified graph buckets/KV capacities because the
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server CLI is unchanged from Trace-PD. The only workload change is `OSL→1`.
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- Fixed-P/PD disables vLLM prefix caching on both sides. Before freezing their
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simulator surfaces, a no-request server-start preflight records the actual
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graph captures and KV-block capacities for every `(TP,MNS)`; no request
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latency or winner is used as calibration.
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- Each real result verifies every request's input/output usage and row-vector
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digest. `OSL=1` produces JSON `null` TPOT samples and is never converted to
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zero.
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## Decision rule and cost
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For every applicable objective, compare the complete 12-cell simulator and
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pooled three-trial real surface: winner match, selected-config real regret,
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and non-tied pair direction agreement. A simulator crash or missing request
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metric is a coverage failure, not a high-latency cell.
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The no-request Fixed runtime preflight is capped at 2 H20-GPUh. Each 36-run
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real surface is estimated at 13 nominal / 41 worst-case H20-GPUh, plus CPU-only
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Frontier replay. Launch logs record the resolved inputs, paths, and duration.
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