50 lines
2.2 KiB
Markdown
50 lines
2.2 KiB
Markdown
# EXP-SIMFID-Q30-FIXED-PRESSURE-SURFACE: high-pressure Fixed-PD / Fixed-PO
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> Status: approved and launching (2026-07-19).
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## Question
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When uniform Fixed-PD is moved from the near-singleton workload to
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`4096 -> 256` at `1.125` request/s/GPU, does Frontier still choose a different
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latency-optimal configuration from real community vLLM 0.20? Does removing
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decode (`4096 -> 1`) change that selection boundary?
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## Setup and decision rule
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- Qwen3-30B-A3B BF16 on dash0 H20; community vLLM 0.20.0.
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- Fixed-PD `4096 -> 256` and Fixed-PO `4096 -> 1`; 257 uniform,
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prefix-disjoint requests; prefix caching off.
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- Rate is frozen at 1.125 request/s/GPU, so global rates are 1.125, 2.25, and
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4.5 request/s for TP1, TP2, and TP4.
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- Surface: `TP in {1,2,4}` x `MNS in {8,16,32,64}`, MBT=8192. Real
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measurements use three fresh-server trials with rotated order.
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- Frontier is `deadc4a`, `piecewise`, the frozen CUDA-event profile plus the
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graph-compatible KERNEL_ONLY profile and measured collectives used by the
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prior Trace-PD comparison. No latency calibration is fitted to this case.
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- Compare exact winners, selected-config real regret, and pairwise order for
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mean/p90 TTFT, E2E, and TPOT where decode exists. SLO is not scored.
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The pressure-probe measurements selected the workload but are excluded from
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the real evaluation pool. A failed or incomplete Frontier cell is a coverage
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failure, not a high-latency observation.
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## Expected output and decision
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The final table has one row per case/objective with Frontier winner, real
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winner, regret, and pairwise agreement. If the old Fixed-PD reversal persists,
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the failure is not an artifact of singleton load. If it disappears, simulator
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fidelity has a load-regime boundary that must be localized. Fixed-PO isolates
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whether decode-state composition is necessary for either outcome.
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The previously reviewed matrix schematic remains the figure prototype:
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`../simulator-tuning-latency-matrix-v0/latency-selection-matrix-schematic.svg`.
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## Provenance
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Remote output root:
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`dash0:/home/admin/cpfs/wjh/aituner/qwen30-fixed-pressure-surface-20260719-r1`.
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The campaign records source/profile/model hashes, runtime versions, GPU
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inventory, per-cell commands, raw request records, and an artifact checksum
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manifest.
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