GPU support
Achieving Optimal GPU Performance with Docling
This guide describes how to maximize GPU performance for Docling pipelines. It covers device selection, pipeline differences, and provides example snippets for configuring batch size and concurrency in the VLM pipeline for both Linux and Windows.
Note
Improvements and optimizations strategies for maximizing the GPU performance is an active topic. Regularly check these guidelines for updates.
Standard Pipeline
Enable GPU acceleration by configuring the accelerator device and concurrency options using Docling's API:
from docling.datamodel.accelerator_options import AcceleratorDevice, AcceleratorOptions
# Configure accelerator options for GPU
accelerator_options = AcceleratorOptions(
    device=AcceleratorDevice.CUDA,  # or AcceleratorDevice.AUTO
)
Batch size and concurrency for document processing are controlled for each stage of the pipeline as:
from docling.datamodel.pipeline_options import (
    ThreadedPdfPipelineOptions,
)
pipeline_options = ThreadedPdfPipelineOptions(
    ocr_batch_size=64,  # default 4
    layout_batch_size=64,  # default 4
    table_batch_size=4,  # currently not using GPU batching
)
Setting a higher page_batch_size will run the Docling models (in particular the layout detection stage) with a GPU batch inference mode.
Complete example
For a complete example see gpu_standard_pipeline.py.
VLM Pipeline
For best GPU utilization, use a local inference server. Docling supports inference servers which exposes the OpenAI-compatible chat completion endpoints. For example:
- vllm: http://localhost:8000/v1/chat/completions(available only on Linux)
- LM Studio: http://localhost:1234/v1/chat/completions(available both on Linux and Windows)
- Ollama: http://localhost:11434/v1/chat/completions(available both on Linux and Windows)
Start the inference server
Here is an example on how to start the vllm inference server with optimum parameters for Granite Docling.
vllm serve ibm-granite/granite-docling-258M \
  --host 127.0.0.1 --port 8000 \
  --max-num-seqs 512 \
  --max-num-batched-tokens 8192 \
  --enable-chunked-prefill \
  --gpu-memory-utilization 0.9
Configure Docling
Configure the VLM pipeline using Docling's VLM options:
from docling.datamodel.pipeline_options import VlmPipelineOptions
vlm_options = VlmPipelineOptions(
    enable_remote_services=True,
    vlm_options={
        "url": "http://localhost:8000/v1/chat/completions",  # or any other compatible endpoint
        "params": {
            "model": "ibm-granite/granite-docling-258M",
            "max_tokens": 4096,
        },
        "concurrency": 64,  # default is 1
        "prompt": "Convert this page to docling.",
        "timeout": 90,
    }
)
Additionally to the concurrency, we also have to set the page_batch_size Docling parameter. Make sure to set settings.perf.page_batch_size >= vlm_options.concurrency.
from docling.datamodel.settings import settings
settings.perf.page_batch_size = 64  # default is 4
Complete example
For a complete example see gpu_vlm_pipeline.py.
Available models
Both LM Studio and Ollama rely on llama.cpp as runtime engine. For using this engine, models have to be converted to the gguf format.
Here is a list of known models which are available in gguf format and how to use them.
TBA.
Performance results
Test data: - Number of pages: 192 - Number of tables: 95
Test infrastructure:
- Instance type: g6e.2xlarge
- CPU: 8 vCPUs, AMD EPYC 7R13
- RAM: 64GB
- GPU: NVIDIA L40S 48GB
- CUDA Version: 13.0, Driver Version: 580.95.05
| Pipeline | Page efficiency | 
|---|---|
| Standard - Inline | 3.1 pages/second | 
| VLM - Inference server (GraniteDocling) | 2.4 pages/second |