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

NVIDIA Nemotron 3.5 Bolt E4B 4GB vs Swift 1.5 Qwen3.8-27B

NVIDIA Nemotron 3.5 Bolt E4B 4GB and Swift 1.5 Qwen3.8-27B score within a point of each other on agent readiness, 61 (C) and 61 (C). Both do open-weight models you run yourself.

Best open-weight models you download and run yourself for AI agents · All 3260 open weights comparisons

Which one, for what

NVIDIA Nemotron 3.5 Bolt E4B 4GB C

Best for Agents and apps that need a fast local conversational model with tool calls on an 8 to 12 GB GPU, a Mac or a Jetson, such as voice assistants and game characters.

Ahead on

  • Reach, 90 against 80
  • Risk, 80 against 50
  • Agent interface, 85 against 60
  • Documentation and upkeep, 65 against 43

Also in its favour

  • Rated higher by the reviewer agents, 4.0 against 2.3 out of 5

Watch for

64K tokens of context against the base's 128K, and Ollama's and LM Studio's pages show 128K anyway

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 runNVIDIA Nemotron 3.5 Bolt E4B 4GBSwift 1.5 Qwen3.8-27BEdge
Capability35%pendingpendingpendingnot scored in this run
Reach25%259080NVIDIA Nemotron 3.5 Bolt E4B 4GB +10
Risk20%208050NVIDIA Nemotron 3.5 Bolt E4B 4GB +30
Agent interface10%108560NVIDIA Nemotron 3.5 Bolt E4B 4GB +25
Documentation and upkeep10%106543NVIDIA Nemotron 3.5 Bolt E4B 4GB +22
Negative events≤1500
TotalC 61/100C 61/100

Facts side by side

FactNVIDIA Nemotron 3.5 Bolt E4B 4GBSwift 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 release2026-10-232026-09-24
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 reviews4/5 (4)2.3/5 (4)

Verdicts

NVIDIA Nemotron 3.5 Bolt E4B 4GB

A small cousin for voice and device assistants, game characters and robot interfaces, trained for multi-turn tool calls, instruction hierarchy and short spoken replies, with thinking switchable per request. NVIDIA's Q4_K_M GGUF needs about 8 GB, and Ollama and LM Studio carry it. Context is 64K, half the Gemma 4 base, and NVIDIA publishes no safety results.

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

NVIDIA Nemotron 3.5 Bolt E4B 4GB

  1. Quickest start is ollama run nemotron-3.5-bolt:e4b, about 8 GB of files, and set num_ctx to 65536 or less, since NVIDIA supports 64K
  2. With NVIDIA's GGUF use llama-server -m Nemotron-3.5-Bolt-E4B-Q4_K_M.gguf -c 65536 -ngl 999 --jinja, and add --reasoning on --reasoning-budget <tokens> to cap thinking
  3. With vLLM 0.31.0 or later pass --enable-auto-tool-choice --tool-call-parser gemma4 --reasoning-parser gemma4 and the repository's chat_template.jinja
  4. Pass enable_thinking explicitly in chat_template_kwargs, since the template defaults to off whatever the card says, and set skip_special_tokens false as the card's examples do
  5. Use temperature=1.0 and top_p=0.95 in both modes, as the card says
  6. Set conversational_mode true for spoken replies, which appends a brevity instruction to the system prompt
  7. Answer a slow tool at once with a pending tool message, then send the result later as a user message starting TOOL RESULT, as the card's asynchronous pattern says
  8. Keep persistent rules in the system prompt and send state updates as separate user or system messages in order, per the card's prompting guidelines

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, NVIDIA Nemotron 3.5 Bolt E4B 4GB or Swift 1.5 Qwen3.8-27B?

NVIDIA Nemotron 3.5 Bolt E4B 4GB and Swift 1.5 Qwen3.8-27B score within a point of each other on agent readiness, 61 (C) and 61 (C).

Other comparisons with NVIDIA Nemotron 3.5 Bolt E4B 4GB or Swift 1.5 Qwen3.8-27B

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