[Help] Extremely Slow First-Time Import in New Conda Environments (torch / torchvision / cupy / PyMuPDF, etc.) with Almost Zero CPU/Disk Usage

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[Help] Extremely Slow First-Time Import in New Conda Environments (torch / torchvision / cupy / PyMuPDF, etc.) with Almost Zero CPU/Disk Usage

Hello, I am encountering an unusual and severe performance problem when using Conda environments on my system. I would greatly appreciate help from the community to determine whether this issue is related to my CPU (Ultra 7 265K) or something else in my environment.

:wrench: My System Configuration

  • CPU: Intel Ultra 7 265K

  • GPU: NVIDIA RTX 5060 Ti

  • RAM: 32 GB

  • Storage: NVMe SSD

  • OS: Windows 11 23H2

  • Conda: Fresh installation of both Anaconda and Miniconda (issue occurs on both)

:snake: Problem Description

In brand-new Conda environments, I encounter the following:

  1. First-time imports of certain libraries are extremely slow, including:

    • torch

    • torchvision

    • cupy

    • PyMuPDF

    • (possibly other large packages)

    :stopwatch: The initial import takes several minutes to over ten minutes.

  2. If I terminate Python and wait more than ~10 minutes, the imports become slow again

    • If I re-import immediately (within ~1 minute) after the first import, the import is fast (a few seconds).

    • But if I wait longer (10+ minutes), the import slows down again dramatically.

  3. During these slow imports, CPU usage is near 0%, and disk activity is also near 0%
    This does not look like normal compilation, I/O, or cache-building behavior.

  4. On another machine with the same OS and similar configuration, everything works normally:

    Reference machine:

    • CPU: Intel 14650

    • GPU: RTX 4060

    • RAM: 32 GB

    • OS: Windows 11 23H2

    → Imports are always fast on this machine.
    The exact same code, same Conda environment, same package versions.

:puzzle_piece: What I Have Already Tried (none resolved the issue)

  • Reinstalled Anaconda / Miniconda

  • Created multiple fresh environments

  • Tried different versions of PyTorch and CUDA

  • Updated GPU drivers

  • Cleared __pycache__ and Conda caches

  • Disabled antivirus (including Windows Defender)

  • Checked Windows Indexing

  • Verified SSD health

  • Disabled Windows Real-Time Protection and Core Isolation

  • Used python -v to trace imports → shows stalls but no clear reason

The issue persists across all attempts.

:red_question_mark: My Questions

Could this be related to the Intel Ultra 7 265K architecture or compatibility with Python/Conda?
Under what circumstances would Python show:

  • extremely slow first-time imports

  • very low CPU usage

  • almost no disk I/O

Is there any known compatibility issue with this CPU series (Meteor Lake / Intel Ultra)?

I am unsure whether this is:

  • a CPU architecture issue

  • some Windows security mechanism

  • a Conda/Python dynamic library loading issue

  • filesystem or signature verification issue

  • or something else entirely

:folded_hands: Any help is greatly appreciated!

I can provide additional data if needed:

  • python -v import logs

  • Process Monitor traces

  • Conda environment details

  • System event logs

Thank you in advance — I’m really hoping to identify the root cause of this unusual behavior.

If you want, I can also write a shorter version or a GitHub Issue–style version.

1 Like
2

Same issue here since 22 nov.
Our artifactory’s “conda-remote” times outs over “https://conda.anaconda.org/conda-forge/linux-64/repodata.json”. The same happens when trying to access in from a browser (Edge) and also from outside the corporate network (Safari and Chrome)