Darwin-27B-KR-V2

Qwen3.5 Hybrid Architecture | ~26B Params | Thinking Mode | 262K Context | BF16 | Apache 2.0


Model Overview

Darwin-27B-KR-V2 is the next evolution of FINAL-Bench/Darwin-27B-KR, enhanced with targeted Korean SFT (Supervised Fine-Tuning) for K-AI Leaderboard optimization.

Built on VIDRAFT's Darwin evolutionary merge lineage, this model inherits strong chain-of-thought reasoning from Darwin-27B-Opus and further refines Korean language capabilities through carefully curated training data targeting MuSR (Multi-Step Reasoning), KMMLU-Pro (Korean domain knowledge), and Metacognitive evaluation.

Key Features

  • Darwin lineage — Evolutionary merge backbone from VIDRAFT's Darwin-27B-Opus
  • K-AI targeted SFT — 1,027 curated Korean reasoning & knowledge pairs
  • Thinking mode<think> tag based step-by-step reasoning
  • 262K context — Ultra-long document processing
  • BF16 — Memory-efficient (~48GB)
  • Apache 2.0 — Free for commercial use

Training

Item Details
Base Model FINAL-Bench/Darwin-27B-KR
Method LoRA SFT (rank=64, alpha=128) + Merge
Data 1,027 Korean SFT pairs (MuSR 428 + KMMLU-Pro 500 + Metacognitive 99)
Epochs 2
Learning Rate 2e-5 (cosine schedule)
Effective Batch 16
Target Modules q/k/v/o_proj, gate/up/down_proj (1.17% trainable)
Hardware 8x NVIDIA B200 (183GB each)
Training Time ~25 minutes
Final Loss 0.66
Precision BF16

SFT Data Composition

Source Count Description
MuSR (Korean) 428 Multi-step reasoning: causal, temporal, spatial, counterfactual
KMMLU-Pro 500 Korean domain knowledge: law, economics, science, history, medicine
Metacognitive 99 Self-correcting reasoning with TICOS framework
Total 1,027 All pairs include <think> reasoning tags

Model Specifications

Property Value
Architecture Qwen3.5 (GatedDeltaNet Hybrid Attention, 64-layer)
Parameters ~26B
Hidden Size 5120
Layers 64
Context Length 262,144 tokens
Precision BF16 (~48GB)
Vocab Size 248,320
Thinking Supported (<think> tags)
License Apache 2.0

VRAM Requirements

Setup VRAM Notes
BF16 (native) ~48 GB Single H100/B200 or 2x A100
4-bit quantized ~14 GB Single RTX 4090
8-bit quantized ~26 GB Single A6000

Usage

Requirements: transformers >= 4.57.0

Transformers

from transformers import AutoTokenizer, AutoModelForCausalLM
import torch

tokenizer = AutoTokenizer.from_pretrained("FINAL-Bench/Darwin-27B-KR-V2")
model = AutoModelForCausalLM.from_pretrained(
    "FINAL-Bench/Darwin-27B-KR-V2",
    torch_dtype=torch.bfloat16,
    device_map="auto",
)

messages = [{"role": "user", "content": "대한민국 헌법재판소의 역할과 권한에 대해 설명해주세요."}]
text = tokenizer.apply_chat_template(messages, tokenize=False, add_generation_prompt=True)
inputs = tokenizer(text, return_tensors="pt").to(model.device)
outputs = model.generate(**inputs, max_new_tokens=4096, do_sample=False)
print(tokenizer.decode(outputs[0][inputs["input_ids"].shape[-1]:], skip_special_tokens=True))

vLLM

vllm serve FINAL-Bench/Darwin-27B-KR-V2 \
    --enforce-eager \
    --max-model-len 32768 \
    --dtype bfloat16

Lineage

Qwen/Qwen3.5-27B
    |
    v
FINAL-Bench/Darwin-27B-Opus (evolutionary merge by VIDRAFT)
    |
    v
FINAL-Bench/Darwin-27B-KR (Korean-specialized variant)
    |
    v
FINAL-Bench/Darwin-27B-KR-V2 (this model, + K-AI targeted SFT)

Acknowledgements


Citation

@misc{darwin_27b_kr_v2_2026,
  title        = {Darwin-27B-KR-V2: Korean-Enhanced Reasoning Model},
  author       = {VIDRAFT},
  year         = {2026},
  publisher    = {Hugging Face},
  howpublished = {\url{https://huggingface.co/FINAL-Bench/Darwin-27B-KR-V2}}
}
Downloads last month
12
Safetensors
Model size
27B params
Tensor type
BF16
·
Inference Providers NEW
This model isn't deployed by any Inference Provider. 🙋 Ask for provider support

Model tree for FINAL-Bench/Darwin-27B-KR-V2

Finetuned
(2)
this model