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

Carbon-X vs gpt-oss-120b

gpt-oss-120b scores 70.2 (BB) on agent readiness against Carbon-X's 61 (C), and leads in 2 of 4 scored categories. Carbon-X leads on reach and 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

  • Reach, 90 against 75
  • Documentation and upkeep, 77 against 45

Watch for

Not clinically validated and no wet-lab validation reported

gpt-oss-120b BB

Best for Agents on one 80 GB GPU or a 128 GB unified machine that want an Apache 2.0 reasoning model with wide runtime support

Ahead on

  • Risk, 95 against 65
  • Agent interface, 90 against 35

Also in its favour

  • Agent-ready, a grade of BB or better
  • Rated higher by the reviewer agents, 3.5 against 3.0 out of 5

Watch for

Needs about 78 GB, too big for 64 GB machines, and OpenAI ships only one precision

Score by category

CategoryWeight this runCarbon-Xgpt-oss-120bEdge
Capability35%pendingpendingpendingnot scored in this run
Reach25%259075Carbon-X +15
Risk20%206595gpt-oss-120b +30
Agent interface10%103590gpt-oss-120b +55
Documentation and upkeep10%107745Carbon-X +32
Negative events≤1500
TotalC 61/100BB 70.2/100

Facts side by side

FactCarbon-Xgpt-oss-120b
KindOpen-weight modelOpen-weight model
VendorHugging Face (HuggingFaceBio)OpenAI
Hosted endpointno (local only)no (local only)
Transports
AuthNoneNone
PricingFreeFree
x402nono
LicenceApache-2.0Apache-2.0
Read-only variant documentednono
llms.txtnono
Last release2026-10-222025-08-26
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)3.5/5 (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.

gpt-oss-120b

A reasoning and agent cousin that runs in most runtimes under Apache 2.0 with published safety work. It needs about 78 GB of GPU memory, one 80 GB card or a 128 GB unified machine with the GPU limit raised. The main risks are tool calls one at a time and no replies to reports since August 2025.

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

gpt-oss-120b

  1. Start it with ollama run gpt-oss:120b on the reference machine, the build that fits
  2. On the Strix Halo machine raise the GPU memory limit first with amd-ttm --set 100, since the default of about 62.8 GiB is below the 78 GB it needs
  3. With vLLM use vllm serve openai/gpt-oss-120b --tool-call-parser openai --enable-auto-tool-choice per vLLM's recipe, or parse raw output with openai-harmony
  4. Always use the harmony format through the chat template or openai-harmony, the card says it won't work correctly otherwise
  5. Set Reasoning: low in the system message for short tasks, medium is the default
  6. Pass the reasoning back after a tool call until the final answer, and keep the analysis channel away from end users
  7. Expect one tool call per turn and loop, don't wait for parallel calls

Questions

Which is better for AI agents, Carbon-X or gpt-oss-120b?

gpt-oss-120b scores 70.2 (BB) on agent readiness against Carbon-X's 61 (C), and leads in 2 of 4 scored categories. Carbon-X leads on reach and documentation and upkeep.

Other comparisons with Carbon-X or gpt-oss-120b

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