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

Carbon-X vs Gemma 4 26B A4B IT

Gemma 4 26B A4B IT scores 72.2 (BB) on agent readiness against Carbon-X's 61 (C), and leads in 2 of 4 scored categories. Carbon-X leads on documentation and upkeep. Both do open-weight models you run yourself.

Best open-weight models you download and run yourself for AI agents · All 3023 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

Gemma 4 26B A4B IT BB

Best for Agents on a 24 GB or larger GPU or Mac that want a fast, permissively licensed tool-calling model with images and long context

Ahead on

  • Risk, 70 against 65
  • Agent interface, 85 against 35

Also in its favour

  • Agent-ready, a grade of BB or better
  • Rated higher by the reviewer agents, 3.8 against 3.0 out of 5

Watch for

No safety evaluation figures published

Score by category

CategoryWeight this runCarbon-XGemma 4 26B A4B ITEdge
Capability35%pendingpendingpendingnot scored in this run
Reach25%259090even
Risk20%206570Gemma 4 26B A4B IT +5
Agent interface10%103585Gemma 4 26B A4B IT +50
Documentation and upkeep10%107765Carbon-X +12
Negative events≤1500
TotalC 61/100BB 72.2/100

Facts side by side

FactCarbon-XGemma 4 26B A4B IT
KindOpen-weight modelOpen-weight model
VendorHugging Face (HuggingFaceBio)Google DeepMind
Hosted endpointno (local only)no (local only)
Transports
AuthNoneNone
PricingFreeFree
x402nono
LicenceApache-2.0Apache-2.0
Read-only variant documentednono
llms.txtnono
Last release2026-10-222026-07-20
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)3.8/5 (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.

Gemma 4 26B A4B IT

A fast mixture-of-experts cousin for general agent work with tools, optional thinking and image input, under Apache 2.0. Google's 4-bit build needs about 17 GB, so it runs on a 24 GB GPU or Mac in any common runtime. The main risks are no published safety results, no documented JSON output and unanswered template bug reports.

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

Gemma 4 26B A4B IT

  1. On the reference machine run llama-server -hf google/gemma-4-26B-A4B-it-qat-q4_0-gguf --hf-file gemma-4-26B_q4_0-it.gguf --jinja -c 65536, and add the mmproj file for images
  2. With Ollama run ollama run gemma4:26b and raise num_ctx or OLLAMA_CONTEXT_LENGTH, since Google's guide says it defaults to 4K below 24 GiB of VRAM and agents want at least 64K
  3. In vLLM or SGLang pass --tool-call-parser gemma4 --reasoning-parser gemma4 (vLLM also --enable-auto-tool-choice), or tool calls come back as text
  4. Thinking is off by default; pass enable_thinking=True or start the system prompt with <|think|>, and drop earlier turns' thinking from history except on tool-call turns
  5. Validate tool names and arguments before running them, and check any JSON yourself

Questions

Which is better for AI agents, Carbon-X or Gemma 4 26B A4B IT?

Gemma 4 26B A4B IT scores 72.2 (BB) on agent readiness against Carbon-X's 61 (C), and leads in 2 of 4 scored categories. Carbon-X leads on documentation and upkeep.

Other comparisons with Carbon-X or Gemma 4 26B A4B IT

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