/data-processing-nemo-curator

name: nemo-curator
description: GPU-accelerated data curation for LLM training. Supports text/image/video/audio. Features fuzzy deduplication (16× faster), quality filtering (30+ heuristics), semantic deduplication, PII redaction, NSFW detection. Scales across GPUs with RAPIDS. Use for preparing high-quality training datasets, cleaning web data, or deduplicating large corpora.
version: 1.0.0
author: Orchestra Research
license: MIT
tags: [Data Processing, NeMo Curator, Data Curation, GPU Acceleration, Deduplication, Quality Filtering, NVIDIA, RAPIDS, PII Redaction, Multimodal, LLM Training Data]
dependencies: [nemo-curator, cudf, dask, rapids]

NeMo Curator - GPU-Accelerated Data Curation

NVIDIA's toolkit for preparing high-quality training data for LLMs.

When to use NeMo Curator

**Use NeMo Curator when:**

• Preparing LLM training data from web scrapes (Common Crawl)
• Need fast deduplication (16× faster than CPU)
• Curating multi-modal datasets (text, images, video, audio)
• Filtering low-quality or toxic content
• Scaling data processing across GPU cluster

**Performance**:

• **16× faster** fuzzy deduplication (8TB RedPajama v2)
• **40% lower TCO** vs CPU alternatives
• **Near-linear scaling** across GPU nodes

**Use alternatives instead**:

• **datatrove**: CPU-based, open-source data processing
• **dolma**: Allen AI's data toolkit
• **Ray Data**: General ML data processing (no curation focus)

Quick start

Installation

# Text curation (CUDA 12)
uv pip install "nemo-curator[text_cuda12]"

# All modalities
uv pip install "nemo-curator[all_cuda12]"

# CPU-only (slower)
uv pip install "nemo-curator[cpu]"

Basic text curation pipeline

from nemo_curator import ScoreFilter, Modify
from nemo_curator.datasets import DocumentDataset
import pandas as pd

# Load data
df = pd.DataFrame({"text": ["Good document", "Bad doc", "Excellent text"]})
dataset = DocumentDataset(df)

# Quality filtering
def quality_score(doc):
    return len(doc["text"].split()) > 5  # Filter short docs

filtered = ScoreFilter(quality_score)(dataset)

# Deduplication
from nemo_curator.modules import ExactDuplicates
deduped = ExactDuplicates()(filtered)

# Save
deduped.to_parquet("curated_data/")

Data curation pipeline

Stage 1: Quality filtering

from nemo_curator.filters import (
    WordCountFilter,
    RepeatedLinesFilter,
    UrlRatioFilter,
    NonAlphaNumericFilter
)

# Apply 30+ heuristic filters
from nemo_curator import ScoreFilter

# Word count filter
dataset = dataset.filter(WordCountFilter(min_words=50, max_words=100000))

# Remove repetitive content
dataset = dataset.filter(RepeatedLinesFilter(max_repeated_line_fraction=0.3))

# URL ratio filter
dataset = dataset.filter(UrlRatioFilter(max_url_ratio=0.2))

Stage 2: Deduplication

**Exact deduplication**:

from nemo_curator.modules import ExactDuplicates

# Remove exact duplicates
deduped = ExactDuplicates(id_field="id", text_field="text")(dataset)

**Fuzzy deduplication** (16× faster on GPU):

from nemo_curator.modules import FuzzyDuplicates

# MinHash + LSH deduplication
fuzzy_dedup = FuzzyDuplicates(
    id_field="id",
    text_field="text",
    num_hashes=260,      # MinHash parameters
    num_buckets=20,
    hash_method="md5"
)

deduped = fuzzy_dedup(dataset)

**Semantic deduplication**:

from nemo_curator.modules import SemanticDuplicates

# Embedding-based deduplication
semantic_dedup = SemanticDuplicates(
    id_field="id",
    text_field="text",
    embedding_model="sentence-transformers/all-MiniLM-L6-v2",
    threshold=0.8  # Cosine similarity threshold
)

deduped = semantic_dedup(dataset)

Stage 3: PII redaction

from nemo_curator.modules import Modify
from nemo_curator.modifiers import PIIRedactor

# Redact personally identifiable information
pii_redactor = PIIRedactor(
    supported_entities=["EMAIL_ADDRESS", "PHONE_NUMBER", "PERSON", "LOCATION"],
    anonymize_action="replace"  # or "redact"
)

redacted = Modify(pii_redactor)(dataset)

Stage 4: Classifier filtering

from nemo_curator.classifiers import QualityClassifier

# Quality classification
quality_clf = QualityClassifier(
    model_path="nvidia/quality-classifier-deberta",
    batch_size=256,
    device="cuda"
)

# Filter low-quality documents
high_quality = dataset.filter(lambda doc: quality_clf(doc["text"]) > 0.5)

GPU acceleration

GPU vs CPU performance

| Operation | CPU (16 cores) | GPU (A100) | Speedup | |-----------|----------------|------------|---------| | Fuzzy dedup (8TB) | 120 hours | 7.5 hours | 16× | | Exact dedup (1TB) | 8 hours | 0.5 hours | 16× | | Quality filtering | 2 hours | 0.2 hours | 10× |

Multi-GPU scaling

from nemo_curator import get_client
import dask_cuda

# Initialize GPU cluster
client = get_client(cluster_type="gpu", n_workers=8)

# Process with 8 GPUs
deduped = FuzzyDuplicates(...)(dataset)

Multi-modal curation

Image curation

from nemo_curator.image import (
    AestheticFilter,
    NSFWFilter,
    CLIPEmbedder
)

# Aesthetic scoring
aesthetic_filter = AestheticFilter(threshold=5.0)
filtered_images = aesthetic_filter(image_dataset)

# NSFW detection
nsfw_filter = NSFWFilter(threshold=0.9)
safe_images = nsfw_filter(filtered_images)

# Generate CLIP embeddings
clip_embedder = CLIPEmbedder(model="openai/clip-vit-base-patch32")
image_embeddings = clip_embedder(safe_images)

Video curation

from nemo_curator.video import (
    SceneDetector,
    ClipExtractor,
    InternVideo2Embedder
)

# Detect scenes
scene_detector = SceneDetector(threshold=27.0)
scenes = scene_detector(video_dataset)

# Extract clips
clip_extractor = ClipExtractor(min_duration=2.0, max_duration=10.0)
clips = clip_extractor(scenes)

# Generate embeddings
video_embedder = InternVideo2Embedder()
video_embeddings = video_embedder(clips)

Audio curation

from nemo_curat