SmolLM3-3B · llama.cpp · Q8_0

status: done

Configuration

ModelHuggingFaceTB/SmolLM3-3B
CompanyHugging Face
FamilySmolLM
Parameters3B
Enginellama.cpp
Quant / precisionQ8_0
Why this quantQ8_0 — near-lossless reference point to quantify Q4_K_M's quality/speed tradeoff.
Downloadggml-org/SmolLM3-3B-GGUF
Context window65536
Input modalitiestext

Measured results

Prefill tok/s914.23
Decode tok/s570.6
Peak memory (GB)17.67 (system MemAvailable delta (10s sampling))
Completed2026-06-21 21:20 +08

Full run command

# llama-server (NGC dispatcher image) + ShareGPT serving benchmark, conc=32
docker run --rm --gpus all -p 8081:8081 -v /home/gauravmm/models:/models:ro \
  ghcr.io/ggml-org/llama.cpp:full-cuda \
  --server -m /models/SmolLM3-Q8_0.gguf -ngl 99 -c 65536 --parallel 32 -cb \
  --host 0.0.0.0 --port 8081
python3 scripts/bench-serving.py --base-url http://localhost:8081 \
  --model SmolLM3-Q8_0.gguf \
  --dataset benchmark_data/ShareGPT_V3_unfiltered_cleaned_split.json \
  --num-prompts 1000 --max-seconds 900 --concurrency 32 --max-tokens 256

smollm3-3b Hugging Face SmolLM Q8_0 ≤4B conc-32

Notes

Q8_0 companion to the Q4_K_M shakedown — the quant axis, re-run under the ShareGPT serving-benchmark methodology (synthetic llama-bench numbers superseded).

  • Workload: real ShareGPT V3 prompts, 1000-entry / 15-min cap. Completed 974/1000 in 428 s at concurrency 32 (same 26 long prompts exceeded the 2048-tok/slot context).
  • Throughput (aggregate, under load): prefill 914.2 tok/s, decode 570.6 tok/s. Per-stream: TTFT median 342 ms, TPOT median 49.1 ms.
  • vs Q4_K_M (same load): decode 570.6 vs 653.6 tok/s — Q8 moves ~2× the bytes per weight and decode is bandwidth-bound, so it’s slower; the gap (≈13%) is much smaller than the single-stream llama-bench gap (70.6 vs 105.7) because at conc 32 the KV-cache traffic, not the weights, dominates bandwidth. Memory 17.67 vs 16.19 GB (≈1.3 GB heavier weights; the 64k KV cache is the bulk of both).
  • GGUF: ggml-org/SmolLM3-3B-GGUFSmolLM3-Q8_0.gguf (3.04 GiB weights). CUDA on the GB10, -ngl 99, continuous batching. llama.cpp build b9744-063d9c156.