gpt-oss-20b · vLLM · MXFP4 · conc 4
status: done
Configuration
| Model | openai/gpt-oss-20b |
|---|---|
| Company | OpenAI |
| Family | gpt-oss |
| Parameters | 21B / 3.6B (MoE) |
| Engine | vLLM |
| Quant / precision | MXFP4 |
| Why this quant | conc-4 base (non-spec) point of gpt-oss-20b — matched no-spec baseline for the EAGLE3 conc-4 row (EXPERIMENTS.md |
| Download | openai/gpt-oss-20b |
| Context window | 65536 |
| Input modalities | text |
Measured results
| Prefill tok/s | 179.74 |
|---|---|
| Decode tok/s | 127.26 |
| Peak memory (GB) | 108.4 (system MemAvailable delta (10s sampling) — vLLM static KV reservation (util 0.85)) |
| Completed | 2026-07-01 15:22 +0800 |
Full run command
# conc-4 base (no spec), cu130-nightly. Harmony vocab via VOCAB_DIR override.
VLLM_IMAGE=vllm/vllm-openai:cu130-nightly VOCAB_DIR=$HOME/tiktoken_encodings \
scripts/bench-vllm-serving.sh openai/gpt-oss-20b 65536 4 1000 600 256
# 313/1000 prompts (hit 600 s cap), 22 harmony errors.
Notes
conc-4 base (no-spec) point of gpt-oss-20b MXFP4 — matched baseline for the EAGLE3 conc-4 row (EXPERIMENTS.md #15). Same cu130-nightly recipe as the published conc-32 base.
- Result (conc 4): prefill 179.74 / decode 127.26 tok/s aggregate; 313/1000 prompts (hit the 600 s cap), 22 harmony errors (rising with batch — 5 at c2 → 22 at c4, mid-reasoning 256-tok truncation); peak mem 108.4 GB.
- Anchors the base line for the EAGLE3 artifact test at conc-4. Base line so far: 83.4 (c2) → 127.3 (c4).
- TTFT/TPOT are buffered-reasoning artifacts — aggregate decode tok/s is the valid metric.
- Base siblings:
-c2·-c16·c32(main). EAGLE3 counterpart:-eagle3-c4.