Renesas/CS3Darknet-ONNX

CS3Darknet (ONNX) – Renesas X5H

Introduction

This repository hosts CS3Darknet-M, targeting the Renesas R-Car X5H platform for image classification inference on the NPX6 NPU.

Note on size variant: The upstream benchmark export identifies this model only as "CS3Darknet", without a size suffix. The compile-artifact filename recorded alongside the benchmark run (cs3darknet_m_quantization_config.json) confirms this is the Medium (M) variant — this repo documents that specific checkpoint.

Resolution discrepancy note: the upstream timm/cs3darknet_m.c2ns_in1k checkpoint's published test resolution is 288×288 (train 256×256), but the GF benchmark run documented below was executed at 224×224. Reported as-measured, without correction.

• Model Architecture: CS3Darknet ("Cross-Stage-3 Darknet") — a CSPNet-lineage Darknet backbone used in the YOLOv3/CSPNet/YOLOv5 line of work, Medium size
• Source Model: timm/cs3darknet_m.c2ns_in1k
• Task: Image Classification (ImageNet-1k, 1000 classes)
• Parameters: 9.3M (timm model card: Params (M): 9.3, GMACs: 2.1)
• Related papers: CSPNet (Wang et al., arXiv:1911.11929), YOLOv3 (Redmon & Farhadi, arXiv:1804.02767), "ResNet strikes back" training recipe (Wightman et al., arXiv:2110.00476)

Deployment Flow

The FP32 ONNX model is auto-cast to INT8 by the Renesas MWMX toolchain at compile time — no separate quantization step is required.

cs3darknet_m_..._optimized.onnx (FP32)
        │
        └─▶  MWMX Runtime  ──▶  INT8 auto-cast  ──▶  NPX6 NPU

Provided Artifacts

Artifact	Status	Notes
FP32 (ONNX)	✅	fp32/cs3darknet_m.onnx — FP32 ONNX export

Performance

Measured on Renesas R-Car X5H via the MWMX runtime (APM50 ship-performance CI pipeline).

Benchmark configuration: Single NPU · Single AI Core · Batch size: 1 · Input: 3 × 224 × 224 (below this checkpoint's published test resolution of 288 × 288 — see note above).

Runtime	Precision	Device	Latency (ms)	Type
MWMX Runtime	INT8 (auto)	X5H · 1× NPU · 1 Core · 850 MHz	2.052662	Measured

Only the 1-AI-core slice was run for this model in the source benchmark export — the 12-core slice was skipped, so no 12-core row is reported here.

Accuracy

TBD — not yet measured/published for this repo.

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Runtime Details

MWMX Runtime

• Engine: Renesas MWMX (Middleware MX) native inference runtime
• Input format: FP32 ONNX (compiled by the MWMX toolchain)
• NPU execution precision: INT8 (auto-cast by MWMX toolchain)
• Execution target: NPX6-48K NPU on R-Car X5H

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Prerequisites

To run inference on Renesas R-Car X5H, you need:

1. Renesas R-Car X5H board with NPX6 NPU
2. Renesas MWMX Runtime
3. Hugging Face CLI to download the model

Download

hf download Renesas/CS3Darknet-ONNX --repo-type=model --include "fp32/*"

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Benchmark Methodology

• HIL runs: Hardware-in-the-loop — measured on physical R-Car X5H silicon via the MWMX runtime (metawaremx_runtime CI pipeline, "APM50" ship-performance target)
• Precision: FP32 ONNX input; INT8 execution (auto-cast by MWMX)
• Slices: only the 1 AI core slice was run for this model; the 12-core slice was skipped in the source export