Cupynumeric Hdf5

---
name: cupynumeric-hdf5
description: >-
  Read and write large cuPyNumeric arrays to HDF5 with Legate's parallel, distributed HDF5 I/O (legate.io.hdf5: to_file, from_file, from_file_batched). Use when a developer needs to save a cuPyNumeric array to an .h5/.hdf5 file, load an HDF5 dataset into a distributed cuPyNumeric array, read a large HDF5 dataset in chunks, hand arrays to an HPC pipeline as a single file, or accelerate HDF5 disk I/O with GPUDirect Storage (GDS). Do not use it for Parquet/cuDF/raw-binary or other sharded/custom layouts (see the cupynumeric-parallel-data-load skill), Zarr or object-store/S3 output, .npz or pickled archives, plain h5py without cuPyNumeric, or pure array compute such as FFT, matmul, or reductions.
license: CC-BY-4.0 OR Apache-2.0
compatibility: >-
  Requires cuPyNumeric and Legate 26.01 or newer (the legate.io.hdf5 module; in 25.03 it lived at legate.core.io.hdf5). Requires h5py (conda install -c conda-forge h5py) - hdf5.py imports it at module load, so the import fails without it. GPUDirect Storage is optional and needs the nv-legate vfd-gds plugin (bundled with legate) plus NVIDIA cuFile.
metadata:
  version: "2.0.0"
  author: "NVIDIA Corporation <legate@nvidia.com>"
  tags:
  - hdf5
  - cupynumeric
  - legate
  - data-io
  - h5py
  - gpudirect-storage
  - parallel-io
  - scientific-data
  upstream: https://github.com/nv-legate/cupynumeric
  docs: https://docs.nvidia.com/legate/latest/api/python/io/index.html
---

# cuPyNumeric HDF5 I/O