Model reference · open weights

h2o-danube3

LLMs h2oai Text gen 1 build Open weights 75k dl/mo

h2o-danube3 is an open-weight language model from h2oai. h2o-danube3-500m-chat (BF16) weighs 1.0 GB; the smallest configuration that runs it is RTX 3060 12 GB.

For self-hosting, compare this build's requirements below with the GPU you plan to rent.

  • h2o-danube3 is a 514M parameter text-generation model developed by h2oai, designed for chat applications.
  • It supports a context length of 8192 tokens and operates in English.
  • The model is released under the apache-2.0 licence.

Summary of the h2oai/h2o-danube3-500m-chat model card, 2026-10-01

What it is

Released byh2oai
Released2024-07-04
Parameters514M
VRAM1.0 GB for the weights

What it runs on

Memory and cards for h2o-danube3-500m-chat (BF16)

1.0 GBweights, file size
49 MBcache per 1K tokens
521 MBruntime overhead, at least
8,192 tokenscontext max
CardRequests at onceContext maxMemory
8K each
RTX 3060 12 GB25all 8K11.6 GB
RTX 4060 Ti 16 GB34all 8K15.4 GB
RTX 3090 24 GB54all 8K23.4 GB
RTX 4090 24 GB54all 8K23.4 GB
RTX 5090 32 GB73all 8K31.0 GB
L40S 48 GB105all 8K44.0 GB
A100 80 GB190all 8K78.2 GB
H100 80 GB183all 8K78.1 GB
RTX PRO 6000 Blackwell 96 GB222all 8K93.8 GB
DGX Spark (GB10) 128 GB unified256all 8K107 GB
H200 141 GB332all 8K138 GB
B200 180 GB426all 8K176 GB
Memory needed at each load
Requests at once8K tokens each
12.0 GB
53.6 GB
84.8 GB
168.0 GB
3214.4 GB
6427.3 GB

One card, with vLLM's small-card settings.

From the model card

What h2oai says about h2o-danube3

Read the model card

alt="Slightly cropped image" style="width: 102%; height: 102%; object-fit: cover; object-position: center; margin: -5% -5% -5% -5%;">

Summary

h2o-danube3-500m-chat is a chat fine-tuned model by H2O.ai with 500 million parameters. We release two versions of this model:

Model NameDescription
h2oai/h2o-danube3-500m-baseBase model
h2oai/h2o-danube3-500m-chatChat model

This model was trained using H2O LLM Studio.

Can be run natively and fully offline on phones - try it yourself with H2O AI Personal GPT.

Model Architecture

We adjust the Llama 2 architecture for a total of around 500m parameters. For details, please refer to our Technical Report. We use the Mistral tokenizer with a vocabulary size of 32,000 and train our model up to a context length of 8,192.

The details of the model architecture are:

HyperparameterValue
n_layers16
n_heads16
n_query_groups8
n_embd1536
vocab size32000
sequence length8192

Usage

To use the model with the transformers library on a machine with GPUs, first make sure you have the transformers library installed.

pip install transformers>=4.42.3
import torch
from transformers import pipeline

pipe = pipeline(
    "text-generation",
    model="h2oai/h2o-danube3-500m-chat",
    torch_dtype=torch.bfloat16,
    device_map="auto",
)

# We use the HF Tokenizer chat template to format each message
# https://huggingface.co/docs/transformers/main/en/chat_templating
messages = [
    {"role": "user", "content": "Why is drinking water so healthy?"},
]
prompt = pipe.tokenizer.apply_chat_template(
    messages,
    tokenize=False,
    add_generation_prompt=True,
)
res = pipe(
    prompt,
    return_full_text=False,
    max_new_tokens=256,
)
print(res[0]["generated_text"])

This will apply and run the correct prompt format out of the box:

Alternatively, one can also run it via:

import torch
from transformers import AutoModelForCausalLM, AutoTokenizer

model_name = "h2oai/h2o-danube3-500m-chat"

tokenizer = AutoTokenizer.from_pretrained(
    model_name,
)
model = AutoModelForCausalLM.from_pretrained(
    model_name,
    torch_dtype=torch.bfloat16,
    device_map="auto",
    trust_remote_code=True,
)

messages = [
    {"role": "user", "content": "Why is drinking water so healthy?"},
]
prompt = tokenizer.apply_chat_template(
    messages,
    tokenize=False,
    add_generation_prompt=True,
)
inputs = tokenizer(
    prompt, return_tensors="pt", add_special_tokens=False
).to("cuda")

# generate configuration can be modified to your needs
tokens = model.generate(
    input_ids=inputs["input_ids"],
    attention_mask=inputs["attention_mask"],
    min_new_tokens=2,
    max_new_tokens=256,
)[0]

tokens = tokens[inputs["input_ids"].shape[1]:]
answer = tokenizer.decode(tokens, skip_special_tokens=True)
print(answer)

Quantization and sharding

You can load the models using quantization by specifying load_in_8bit=True or load_in_4bit=True. Also, sharding on multiple GPUs is possible by setting device_map=auto.

Model Architecture

LlamaForCausalLM(
  (model): LlamaModel(
    (embed_tokens): Embedding(32000, 1536, padding_idx=0)
    (layers): ModuleList(
      (0-15): 16 x LlamaDecoderLayer(
        (self_attn): LlamaSdpaAttention(
          (q_proj): Linear(in_features=1536, out_features=1536, bias=False)
          (k_proj): Linear(in_features=1536, out_features=768, bias=False)
          (v_proj): Linear(in_features=1536, out_features=768, bias=False)
          (o_proj): Linear(in_features=1536, out_features=1536, bias=False)
          (rotary_emb): LlamaRotaryEmbedding()
        )
        (mlp): LlamaMLP(
          (gate_proj): Linear(in_features=1536, out_features=4096, bias=False)
          (up_proj): Linear(in_features=1536, out_features=4096, bias=False)
          (down_proj): Linear(in_features=4096, out_features=1536, bias=False)
          (act_fn): SiLU()
        )
        (input_layernorm): LlamaRMSNorm()
        (post_attention_layernorm): LlamaRMSNorm()
      )
    )
    (norm): LlamaRMSNorm()
  )
  (lm_head): Linear(in_features=1536, out_features=32000, bias=False)
)

Benchmarks

🤗 Open LLM Leaderboard v1

Benchmarkacc_n
Average40.71
ARC-challenge39.25
Hellaswag61.02
MMLU26.33
TruthfulQA39.96
Winogrande61.72
GSM8K16.00

MT-Bench

First Turn: 4.16
Second Turn: 2.40
Average: 3.28

Disclaimer

Please read this disclaimer carefully before using the large language model provided in this repository. Your use of the model signifies your agreement to the following terms and conditions.

  • Biases and Offensiveness: The large language model is trained on a diverse range of internet text data, which may contain biased, racist, offensive, or otherwise inappropriate content. By using this model, you acknowledge and accept that the generated content may sometimes exhibit biases or produce content that is offensive or inappropriate. The developers of this repository do not endorse, support, or promote any such content or viewpoints.
  • Limitations: The large language model is an AI-based tool and not a human. It may produce incorrect, nonsensical, or irrelevant responses. It is the user's responsibility to critically evaluate the generated content and use it

Quoted from the model card on Hugging Face. The full card is behind the Hugging Face link above.

© 2026 AxForge · EU-hosted AI infrastructure Pricing Docs Trust Privacy Terms