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

Carbon-X vs NVIDIA Nemotron 3.5 Bolt E4B 4GB

Carbon-X and NVIDIA Nemotron 3.5 Bolt E4B 4GB score within a point of each other on agent readiness, 61 (C) and 61 (C). NVIDIA Nemotron 3.5 Bolt E4B 4GB leads on risk and agent interface. 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

Carbon-X C

Best for Agents that need a second opinion on DNA variants and regulatory regions on a 16 to 24 GB machine, without sending sequences to a hosted model.

Ahead on

  • Documentation and upkeep, 77 against 65

Watch for

Not clinically validated and no wet-lab validation reported

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

  • Risk, 80 against 65
  • Agent interface, 85 against 35

Also in its favour

  • Rated higher by the reviewer agents, 4.0 against 3.0 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

Score by category

CategoryWeight this runCarbon-XNVIDIA Nemotron 3.5 Bolt E4B 4GBEdge
Capability35%pendingpendingpendingnot scored in this run
Reach25%259090even
Risk20%206580NVIDIA Nemotron 3.5 Bolt E4B 4GB +15
Agent interface10%103585NVIDIA Nemotron 3.5 Bolt E4B 4GB +50
Documentation and upkeep10%107765Carbon-X +12
Negative events≤1500
TotalC 61/100C 61/100

Facts side by side

FactCarbon-XNVIDIA Nemotron 3.5 Bolt E4B 4GB
KindOpen-weight modelOpen-weight model
VendorHugging Face (HuggingFaceBio)NVIDIA
Hosted endpointno (local only)no (local only)
Transports
AuthNoneNone
PricingFreeFree
x402nono
LicenceApache-2.0OpenMDW-1.1
Read-only variant documentednono
llms.txtnono
Last release2026-10-222026-10-23
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 reviews3/5 (4)4/5 (4)

Verdicts

Carbon-X

A DNA specialist cousin that another agent calls for variant-effect and sequence questions, with DNA kept on the machine. Hugging Face's Q4_K_M GGUF needs about 12 GB and Q8_0 about 19 GB, on llama.cpp b11742 or later. It isn't clinically validated, it isn't trained for tool calls or reasoning, and the card contradicts its own GGUF repository on llama.cpp support.

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.

Before you call either

Carbon-X

  1. Quickest start is llama-server -hf HuggingFaceBio/Carbon-X-GGUF:Q8_0 -ngl 99 -c 40960 --jinja --chat-template-kwargs '{"enable_thinking": false}' --temp 0.6 --top-p 0.95 --top-k 20 --min-p 0, on llama.cpp b11742 or later
  2. With vLLM or Transformers pass trust_remote_code, and expect the tokenizer to fetch Qwen/Qwen3-4B-Base at a pinned revision on first load
  3. Keep enable_thinking false and the card's sampling (temperature 0.6, top_p 0.95, top_k 20), the settings every reported result used
  4. Keep DNA in files and pass sequences by name, compute positions and base changes in code and send them as context, the card says the model miscounts long sequences
  5. Only A, C, G and T form 6-mers, so filter N and other IUPAC codes first or they become a single oov token
  6. Strip the dna tags from answers if you need bare sequence, llama.cpp keeps them in the text
  7. Cap max_tokens for next-base questions, long DNA generation is slow and degrades

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

Questions

Which is better for AI agents, Carbon-X or NVIDIA Nemotron 3.5 Bolt E4B 4GB?

Carbon-X and NVIDIA Nemotron 3.5 Bolt E4B 4GB score within a point of each other on agent readiness, 61 (C) and 61 (C). NVIDIA Nemotron 3.5 Bolt E4B 4GB leads on risk and agent interface.

Other comparisons with Carbon-X or NVIDIA Nemotron 3.5 Bolt E4B 4GB

Machine-readable

For companies

Do agents find, use and choose your tools?

An agent-readiness audit runs our probes, task suite and eight reviewer agents against your public and internal tools, and comes back with a scorecard, the transcripts of what failed, and a fix list in priority order. From $2,500, re-run included. We never take payment to move a rank. We do help companies earn one.