Model reference · open weights

internlm2_5-1

LLMs internlm Text gen 2 builds Its own licence terms 6k dl/mo

internlm2_5-1 is an open-weight language model from internlm. internlm2_5-1_8b-chat (BF16) weighs 3.8 GB; the smallest configuration that runs it is RTX 3060 12 GB.

  • InternLM2.5-1.8B-Chat is a text-generation model developed by internlm with 1.9B parameters and a context length of 32,768 tokens.
  • It is designed for practical scenarios, featuring strong reasoning capabilities and support for tool use.
  • The model weights are available for academic research and free commercial usage under a custom license.

Summary of the internlm/internlm2_5-1_8b-chat model card, 2026-10-01

What it is

Released byinternlm
Released2024-07-30
Parameters1.9B
VRAM3.8 GB for the weights

What it runs on

Memory and cards for internlm2_5-1_8b-chat (BF16)

3.8 GBweights, file size
98 MBcache per 1K tokens
625 MBruntime overhead, at least
32,768 tokenscontext max
CardRequests at onceContext maxMemory
8K each32K each
RTX 3060 12 GB82all 32K11.6 GB
RTX 4060 Ti 16 GB133all 32K15.4 GB
RTX 3090 24 GB235all 32K23.4 GB
RTX 4090 24 GB235all 32K23.4 GB
RTX 5090 32 GB338all 32K31.0 GB
L40S 48 GB4912all 32K44.0 GB
A100 80 GB9122all 32K78.2 GB
H100 80 GB8721all 32K78.1 GB
RTX PRO 6000 Blackwell 96 GB10626all 32K93.8 GB
DGX Spark (GB10) 128 GB unified12330all 32K107 GB
H200 141 GB16140all 32K138 GB
B200 180 GB20852all 32K176 GB
Memory needed at each load
Requests at once8K tokens each32K tokens each
15.2 GB7.6 GB
58.4 GB20.5 GB
810.8 GB30.2 GB
1617.3 GB55.9 GB
3230.2 GB107 GB
6455.9 GB211 GB

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

Builds

Sizes, precisions & builds

BuildParamsPrecisionWeightsSmallest setup
internlm2_5-1_8b-chat (above) ↗ 1.9BBF16 3.8 GBRTX 3060 12 GB
internlm2_5-1_8b ↗ —BF16 3.8 GBRTX 3060 12 GB

From the model card

What internlm says about internlm2_5-1

Read the model card

💻Github Repo • 🤔Reporting Issues • 📜Technical Report

Introduction

InternLM2.5 has open-sourced a 1.8 billion parameter base model and a chat model tailored for practical scenarios. The model has the following characteristics:

  • Outstanding reasoning capability: State-of-the-art performance on Math reasoning, surpassing models like MiniCPM-2 and Qwen2-1.5B.

  • Stronger tool use: InternLM2.5 supports gathering information from more than 100 web pages, corresponding implementation has be released in MindSearch. InternLM2.5 has better tool utilization-related capabilities in instruction following, tool selection and reflection. See examples.

InternLM2.5-1.8B-Chat

Performance Evaluation

We conducted a comprehensive evaluation of InternLM using the open-source evaluation tool OpenCompass. The evaluation covered five dimensions of capabilities: disciplinary competence, language competence, knowledge competence, inference competence, and comprehension competence. Here are some of the evaluation results, and you can visit the OpenCompass leaderboard for more evaluation results.

BenchmarkInternLM2.5-1.8B-ChatMiniCPM-2Qwen2-1.5B-Instruct
MMLU (5-shot)50.754.255.7
CMMLU (5-shot)62.250.665.2
BBH (3-shot CoT)41.941.536.5
MATH (0-shot CoT)40.215.521.4
GPQA (0-shot)27.823.727.3
  • The evaluation results were obtained from OpenCompass, and evaluation configuration can be found in the configuration files provided by OpenCompass.
  • The evaluation data may have numerical differences due to the version iteration of OpenCompass, so please refer to the latest evaluation results of OpenCompass.

Limitations: Although we have made efforts to ensure the safety of the model during the training process and to encourage the model to generate text that complies with ethical and legal requirements, the model may still produce unexpected outputs due to its size and probabilistic generation paradigm. For example, the generated responses may contain biases, discrimination, or other harmful content. Please do not propagate such content. We are not responsible for any consequences resulting from the dissemination of harmful information.

Import from Transformers

To load the InternLM2.5 1.8B Chat model using Transformers, use the following code:

import torch
from transformers import AutoTokenizer, AutoModelForCausalLM
tokenizer = AutoTokenizer.from_pretrained("internlm/internlm2_5-1_8b-chat", trust_remote_code=True)
# Set `torch_dtype=torch.float16` to load model in float16, otherwise it will be loaded as float32 and cause OOM Error.
model = AutoModelForCausalLM.from_pretrained("internlm/internlm2_5-1_8b-chat", torch_dtype=torch.float16, trust_remote_code=True).cuda()
model = model.eval()
response, history = model.chat(tokenizer, "hello", history=[])
print(response)
# Hello! How can I help you today?
response, history = model.chat(tokenizer, "please provide three suggestions about time management", history=history)
print(response)

The responses can be streamed using stream_chat:

import torch
from transformers import AutoModelForCausalLM, AutoTokenizer

model_path = "internlm/internlm2_5-1_8b-chat"
model = AutoModelForCausalLM.from_pretrained(model_path, torch_dtype=torch.float16, trust_remote_code=True).cuda()
tokenizer = AutoTokenizer.from_pretrained(model_path, trust_remote_code=True)

model = model.eval()
length = 0
for response, history in model.stream_chat(tokenizer, "Hello", history=[]):
    print(response[length:], flush=True, end="")
    length = len(response)

Deployment

llama.cpp

internlm/internlm2_5-1_8b-chat-gguf offers internlm2_5-1_8b-chat models in GGUF format in both half precision and various low-bit quantized versions, including q5_0, q5_k_m, q6_k, and q8_0.

LMDeploy

LMDeploy is a toolkit for compressing, deploying, and serving LLM, developed by the MMRazor and MMDeploy teams.

pip install lmdeploy

You can run batch inference locally with the following python code:

import lmdeploy
pipe = lmdeploy.pipeline("internlm/internlm2_5-1_8b-chat")
response = pipe(["Hi, pls intro yourself", "Shanghai is"])
print(response)

Or you can launch an OpenAI compatible server with the following command:

lmdeploy serve api_server internlm/internlm2_5-1_8b-chat --model-name internlm2_5-1_8b-chat --server-port 23333

Then you can send a chat request to the server:

curl http://localhost:23333/v1/chat/completions \
    -H "Content-Type: application/json" \
    -d '{
    "model": "internlm2_5-1_8b-chat",
    "messages": [
    {"role": "system", "content": "You are a helpful assistant."},
    {"role": "user", "content": "Introduce deep learning to me."}
    ]
    }'

Find more details in the LMDeploy documentation

vLLM

Launch OpenAI compatible server with vLLM>=0.3.2:

pip install vllm
python -m vllm.entrypoints.openai.api_serve

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

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