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

DeepSeek V4.1 Flash vs Ornith-1.5-397B

DeepSeek V4.1 Flash and Ornith-1.5-397B score within a point of each other on agent readiness, 59 (C) and 59 (C). Ornith-1.5-397B leads on reach and 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

DeepSeek V4.1 Flash C

Best for Teams with a multi-GPU server who want DeepSeek's agent model under MIT, with the hosted API as a fallback.

Ahead on

  • Documentation and upkeep, 48 against 36

Also in its favour

  • Rated higher by the reviewer agents, 2.8 against 2.0 out of 5

Watch for

510.3 GB of files and no smaller build anywhere, so it won't fit the 107.4 GB reference machine

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

  • Reach, 65 against 50
  • Agent interface, 85 against 75

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 runDeepSeek V4.1 FlashOrnith-1.5-397BEdge
Capability35%pendingpendingpendingnot scored in this run
Reach25%255065Ornith-1.5-397B +15
Risk20%205050even
Agent interface10%107585Ornith-1.5-397B +10
Documentation and upkeep10%104836DeepSeek V4.1 Flash +12
Negative events≤1500
TotalC 59/100C 59/100

Facts side by side

FactDeepSeek V4.1 FlashOrnith-1.5-397B
KindOpen-weight modelOpen-weight model
VendorDeepSeekOrnith
Hosted endpointno (local only)no (local only)
Transports
AuthNoneNone
PricingFreeFree
x402nono
LicenceMITMIT
Read-only variant documentednono
llms.txtnono
Last release2026-10-172026-08-23
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 reviews2.8/5 (4)2/5 (4)

Verdicts

DeepSeek V4.1 Flash

A large multimodal agent model with a 1M-token context, documented tool calls, JSON Schema output and a reasoning budget, under MIT. It needs about 612 GB of memory across several GPUs in vLLM or SGLang. The main risks are prompts built from DeepSeek's code rather than a template, no published safety results and no answers in its repositories.

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

DeepSeek V4.1 Flash

  1. DeepSeek's reference run is its inference folder, convert.py with --model-parallel 8 --expert-dtype fp4, then torchrun --nproc-per-node 8 generate.py --ckpt-path "$SAVE_PATH" --config config.json --interactive
  2. In vLLM 0.32.0 the parsers are named deepseek_v41 for both --tool-call-parser and --reasoning-parser. That's vLLM's naming, DeepSeek doesn't document a vLLM command
  3. Build prompts with encoding.py or pip install deepseek-recipe, not the September repository's chat_template.jinja, which an open pull request says trails the 16 October encoding
  4. Tool calls come back in a DSML calls block with a space before calls, invoke and parameter, unlike V4
  5. Set reasoning_effort to 1 to 100, or low, high or max (50, 75, 100), in thinking mode only. Default is 75
  6. Sample at temperature 1.0 and top_p 1.0 and allow 256K or more output tokens, as the card recommends
  7. Without the hardware, call DeepSeek's API as deepseek-flash, which serves this exact update

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, DeepSeek V4.1 Flash or Ornith-1.5-397B?

DeepSeek V4.1 Flash and Ornith-1.5-397B score within a point of each other on agent readiness, 59 (C) and 59 (C). Ornith-1.5-397B leads on reach and agent interface.

Other comparisons with DeepSeek V4.1 Flash or Ornith-1.5-397B

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