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

Nemotron 3.5 Lightning 30B A3B vs Swift 1.5 Qwen3.8-27B

Nemotron 3.5 Lightning 30B A3B scores 64.2 (B) on agent readiness against Swift 1.5 Qwen3.8-27B's 61 (C), and leads in every scored category. 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

Nemotron 3.5 Lightning 30B A3B B

Best for Agents on one 24 to 32 GB GPU or Mac that want a fast tool-calling reasoning model with long context and a permissive licence

Ahead on

  • Reach, 85 against 80
  • Risk, 75 against 50
  • Agent interface, 90 against 60
  • Documentation and upkeep, 70 against 43

Also in its favour

  • Rated higher by the reviewer agents, 3.0 against 2.3 out of 5

Watch for

No safety evaluation results published

Swift 1.5 Qwen3.8-27B C

Best for Agents on a 24 to 32 GB GPU or Mac that want Qwen3.8-27B's skills with shorter thinking, for teams under US$1M revenue or research.

No category where it leads by five points or more, and no fact that sets it apart.

Watch for

Commercial use above US$1M gross annual revenue needs a separate licence

Score by category

CategoryWeight this runNemotron 3.5 Lightning 30B A3BSwift 1.5 Qwen3.8-27BEdge
Capability35%pendingpendingpendingnot scored in this run
Reach25%258580Nemotron 3.5 Lightning 30B A3B +5
Risk20%207550Nemotron 3.5 Lightning 30B A3B +25
Agent interface10%109060Nemotron 3.5 Lightning 30B A3B +30
Documentation and upkeep10%107043Nemotron 3.5 Lightning 30B A3B +27
Negative events≤1500
TotalB 64.2/100C 61/100

Facts side by side

FactNemotron 3.5 Lightning 30B A3BSwift 1.5 Qwen3.8-27B
KindOpen-weight modelOpen-weight model
VendorNVIDIAUkisAI
Hosted endpointno (local only)no (local only)
Transports
AuthNoneNone
PricingFreeFree
x402nono
LicenceOpenMDW-1.1Swift Open License v1.0 (custom, not an OSI licence) on UkisAI's changes, free for commercial use below US$1M gross annual revenue with a separate Swift Enterprise License above it. Built on Qwen3.8-27B, whose Apache 2.0 still governs the base
Read-only variant documentednono
llms.txtnono
Last release2026-08-112026-09-24
Terms last updatedno 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 reviews3/5 (4)2.3/5 (4)

Verdicts

Nemotron 3.5 Lightning 30B A3B

A small agent cousin, 3B active parameters, with trained parallel tool calls, a thinking switch and up to 1M tokens of context, under a permissive licence. It runs in about 23 GB from the GGUF or Ollama builds, and NVIDIA's NVFP4 build needs NVIDIA GPUs. The main risks are no published safety results and one answered question across two repositories.

Swift 1.5 Qwen3.8-27B

A Qwen3.8-27B cousin post-trained to think in fewer tokens, for coding and agent work with images in, that fits a 24 GB machine with UkisAI's own 4-bit builds. Commercial use is free only below US$1M revenue. The main risks are that nobody at UkisAI answers its discussions, and that the shorter thinking rests on UkisAI's own benchmarks.

Before you call either

Nemotron 3.5 Lightning 30B A3B

  1. Quickest start is ollama run nemotron-3.5-lightning, about 19 to 25 GB of files depending on the platform
  2. On the reference machine use llama-server -hf ggml-org/NVIDIA-Nemotron-3.5-Lightning-30B-A3B-GGUF:Q4_0 --jinja, since the card's Q4_K_M tag doesn't exist there and NVFP4 needs NVIDIA GPUs
  3. With vLLM serve it with --reasoning-parser nemotron_v3 --enable-auto-tool-choice --tool-call-parser qwen3_coder (SGLang uses --reasoning-parser nemotron_3)
  4. Use temperature=1.0 and top_p=0.95, as the card says
  5. Thinking is on by default. Pass chat_template_kwargs with enable_thinking false for short tasks
  6. For coding agents pass force_nonempty_content: true in chat_template_kwargs, which vLLM's nemotron_v3 parser reads so a cut-off reasoning trace still returns content
  7. Go past 262,144 tokens only with the card's flags (VLLM_ALLOW_LONG_MAX_MODEL_LEN=1, --max-model-len 1048576) and enough memory

Swift 1.5 Qwen3.8-27B

  1. Quickest start is llama-server -hf ukisai/Swift-1.5-Qwen3.8-27B-GGUF:Q4_K_M --jinja, about 18.4 GB with the vision projector
  2. On our reference machine BF16 fits, vllm serve ukisai/Swift-1.5-Qwen3.8-27b --max-model-len 262144 --reasoning-parser qwen3 --enable-auto-tool-choice --tool-call-parser qwen3_coder
  3. The template is Qwen3.8-27B's, so chat_template_kwargs with reasoning_effort low, medium or xhigh (default) and enable_thinking false work as on the base
  4. UkisAI benchmarked it at temperature 1.0, top_p 0.95, top_k 20 and presence_penalty 0, which is a reasonable starting point
  5. The MLX 4-bit build needs UkisAI's patched MLX-LM and has no image or video chat
  6. Check the licence before commercial use, it stops at US$1M gross annual revenue including affiliates
  7. MTP self-speculative decoding is available with the base's head, flags on the card

Questions

Which is better for AI agents, Nemotron 3.5 Lightning 30B A3B or Swift 1.5 Qwen3.8-27B?

Nemotron 3.5 Lightning 30B A3B scores 64.2 (B) on agent readiness against Swift 1.5 Qwen3.8-27B's 61 (C), and leads in every scored category.

Other comparisons with Nemotron 3.5 Lightning 30B A3B or Swift 1.5 Qwen3.8-27B

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