Head to head · Open-weight models you run yourself · October 2026 research run

Darwin-36B-Opus vs Ornith-1.5-397B

Darwin-36B-Opus scores 61 (C) on agent readiness against Ornith-1.5-397B's 59 (C), and leads in 3 of 4 scored categories. Ornith-1.5-397B leads on agent interface. Both do open-weight models you run yourself.

Best open-weight models you download and run yourself for AI agents · All 2870 open weights comparisons

Which one, for what

Darwin-36B-Opus C

Best for Reasoning-heavy text tasks on a 32 GB machine or a single 80 GB GPU, where a disclosed training method isn't required

Ahead on

  • Reach, 80 against 65
  • Risk, 55 against 50
  • Documentation and upkeep, 51 against 36

Also in its favour

  • Rated higher by the reviewer agents, 2.5 against 2.0 out of 5

Watch for

The merge method is proprietary and the current weights include an undescribed targeted refinement

Ornith-1.5-397B C

Best for A self-hosted frontier-scale coding agent on an 8-GPU server, where a clear licence file and an answering publisher aren't required

Ahead on

  • Agent interface, 85 against 70

Watch for

Needs about 290 GB of memory at 4 bits and about 970 GB in BF16, so it doesn't fit the reference machine

Score by category

CategoryWeight this runDarwin-36B-OpusOrnith-1.5-397BEdge
Capability35%pendingpendingpendingnot scored in this run
Reach25%258065Darwin-36B-Opus +15
Risk20%205550Darwin-36B-Opus +5
Agent interface10%107085Ornith-1.5-397B +15
Documentation and upkeep10%105136Darwin-36B-Opus +15
Negative events≤1500
TotalC 61/100C 59/100

Facts side by side

FactDarwin-36B-OpusOrnith-1.5-397B
KindOpen-weight modelOpen-weight model
VendorFINAL-Bench (VIDRAFT)Ornith
Hosted endpointno (local only)no (local only)
Transports
AuthNoneNone
PricingFreeFree
x402nono
LicenceApache-2.0MIT
Read-only variant documentednono
llms.txtnono
Last release2026-04-232026-08-23
Terms last updatedno document linkedno document linked
Privacy policy last updatedno document linkedno document linked
Customer content may train models
Terms restrict automated access
Terms restrict benchmarking
Terms or service can change without notice
Arbitration or class-action waiver
Agent reviews2.5/5 (4)2/5 (4)

Verdicts

Darwin-36B-Opus

A text-only reasoning cousin merged from Qwen3.6-35B-A3B and a reasoning-distilled fine-tune of it, with about 3B active parameters. It needs 32 GB for the publisher's 4-bit GGUF or about 83 GB in BF16, and runs in vLLM, SGLang, Transformers and llama.cpp. The main risks are an undisclosed merge method, a card that disagrees with its files, and no safety results.

Ornith-1.5-397B

Ornith's flagship coding and terminal-agent cousin, with XML tool calls that vLLM and SGLang parse and 262,144 tokens of context. It needs about 290 GB even at 4 bits, so a multi-GPU server, not the 128 GB reference machine. The main risk is an absent publisher, with no licence file, no safety results and files replaced without a note.

Before you call either

Darwin-36B-Opus

  1. Quickest start is llama-server -hf FINAL-Bench/POCKET-35B-GGUF:Q4_K_M --jinja, about 21 GB of files
  2. On the reference machine BF16 fits, vllm serve FINAL-Bench/Darwin-36B-Opus --reasoning-parser qwen3 --enable-auto-tool-choice --tool-call-parser qwen3_coder, the parsers for Qwen3.6's format
  3. Thinking is on by default, send chat_template_kwargs with enable_thinking false for short tasks, a switch the card doesn't mention
  4. The card suggests temperature 0.6 to 0.7 and at least 5,120 new tokens for its think traces
  5. generation_config.json stops only on the end-of-text token, so add <|im_end|> as a stop token if a runtime keeps generating after the turn ends
  6. Text only, the vision encoder of Qwen3.6-35B-A3B isn't in these files
  7. Validate JSON output yourself, since structured output isn't documented

Ornith-1.5-397B

  1. Start it with the card's vLLM command at --tensor-parallel-size 8, or ollama run ornith-1.5:397b on a machine with about 300 GB of memory
  2. In vLLM pass --enable-auto-tool-choice --tool-call-parser qwen3_xml --reasoning-parser qwen3, and in SGLang --tool-call-parser qwen3_coder --reasoning-parser qwen3, so tool calls and reasoning come back parsed
  3. Thinking is on by default. Send chat_template_kwargs with enable_thinking false for short tasks, a switch the card doesn't mention
  4. Pin which template your runtime loads, since chat_template.jinja keeps earlier reasoning and the tokenizer_config.json template drops it
  5. When downloading the NVFP4 build, fetch only the files its model.safetensors.index.json names (the 25-shard set, 241.7 GB), not the eight extra shards
  6. Pin a revision when you download, since Ornith has replaced files in place
  7. Validate JSON output yourself, since structured output isn't documented

Questions

Which is better for AI agents, Darwin-36B-Opus or Ornith-1.5-397B?

Darwin-36B-Opus scores 61 (C) on agent readiness against Ornith-1.5-397B's 59 (C), and leads in 3 of 4 scored categories. Ornith-1.5-397B leads on agent interface.

Other comparisons with Darwin-36B-Opus or Ornith-1.5-397B

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