Hi Aneel,

  Technically Boltz can run with the quite old Torch 2.2.2 which is available for Intel Mac.  Torch does not support GPU acceleration on Intel Macs so it will be incredibly slow.  But you could in theory run CPU predictions.  This is a bit tricky to setup since ChimeraX uses a special versions of Boltz (https://github.com/RBVI/boltz) that requires torch 2.7.1 so you would have to clone that repository, change the requirement in pyproject.toml to 2.2.2 and create and install in a Python virtual environment for use by ChimeraX.

Tom

On Nov 25, 2025, at 12:26 PM, Aggarwal, Aneel <aneel.aggarwal@mssm.edu> wrote:

Thanks Tom-

I suspected that might be the problem (processor 3.6 GHz 10-Core Intel Core i9). I guess time to upgrade.

Thanks again,
Aneel

________________________________________
From: Tom Goddard <goddard@sonic.net>
Sent: Tuesday, November 25, 2025 3:19 PM
To: Aggarwal, Aneel
Cc: chimerax-users@cgl.ucsf.edu
Subject: Re: [chimerax-users] Unable to install boltz - please help

USE CAUTION: External Message.

Hi Aneel,

 Are you using an Intel Mac?  Unfortunately the machine learning PyTorch package that Boltz uses stopped supporting Intel Macs so it will only run on Apple Silicon Macs (ARM M1,M2,M3,M4,... processors).

 I'll add an error message to Mac ChimeraX to explain that Boltz cannot be installed on Intel Mac.

       Tom


On Nov 25, 2025, at 11:50 AM, Aggarwal, Aneel via ChimeraX-users <chimerax-users@cgl.ucsf.edu> wrote:

Hello,

I am a new user and trying to use boltz on my iMac (Tahoe OS) and get the error below. Any suggestions?

Thanks,
Aneel


Successfully created Boltz Python virtual environment /Users/aneel/boltz22.
Now installing Boltz and required packages from PyPi. This may take tens of of minutes since Boltz uses many other packages totaling about 1 Gbyte of disk space including torch, scipy, rdkit, llvmlite, sympy, pandas, numpy, wandb, numba...
/Users/aneel/boltz22/bin/python -m pip install https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_RBVI_boltz_archive_chimerax-5Fboltz22.zip&d=DwIFaQ&c=shNJtf5dKgNcPZ6Yh64b-ALLUrcfR-4CCQkZVKC8w3o&r=LWhUW6RvNSf0cLDVthUN3r_hd5b5U0qKDrBXQQX78vo&m=SmYIyI_rTKCMR7Oo-z2avM-pKEjD_MuawtqBEJuo_5mn1R1BG0M01mKnt46LfXyI&s=iWueqthPnXstOjC771kWa3CmsOvbqRG88cDVput-0qE&e=
Collecting https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_RBVI_boltz_archive_chimerax-5Fboltz22.zip&d=DwIFaQ&c=shNJtf5dKgNcPZ6Yh64b-ALLUrcfR-4CCQkZVKC8w3o&r=LWhUW6RvNSf0cLDVthUN3r_hd5b5U0qKDrBXQQX78vo&m=SmYIyI_rTKCMR7Oo-z2avM-pKEjD_MuawtqBEJuo_5mn1R1BG0M01mKnt46LfXyI&s=iWueqthPnXstOjC771kWa3CmsOvbqRG88cDVput-0qE&e=

Using cached https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_RBVI_boltz_archive_chimerax-5Fboltz22.zip&d=DwIFaQ&c=shNJtf5dKgNcPZ6Yh64b-ALLUrcfR-4CCQkZVKC8w3o&r=LWhUW6RvNSf0cLDVthUN3r_hd5b5U0qKDrBXQQX78vo&m=SmYIyI_rTKCMR7Oo-z2avM-pKEjD_MuawtqBEJuo_5mn1R1BG0M01mKnt46LfXyI&s=iWueqthPnXstOjC771kWa3CmsOvbqRG88cDVput-0qE&e=

Installing build dependencies: started

Installing build dependencies: finished with status 'done'

Getting requirements to build wheel: started

Getting requirements to build wheel: finished with status 'done'

Preparing metadata (pyproject.toml): started

Preparing metadata (pyproject.toml): finished with status 'done'

INFO: pip is looking at multiple versions of boltz to determine which version is compatible with other requirements. This could take a while.

ERROR: Could not find a version that satisfies the requirement torch==2.7.1 (from boltz) (from versions: 2.0.0, 2.0.1, 2.1.0, 2.1.1, 2.1.2, 2.2.0, 2.2.1, 2.2.2)

ERROR: No matching distribution found for torch==2.7.1



[notice] A new release of pip is available: 24.0 -> 25.3

[notice] To update, run: /Users/aneel/boltz22/bin/python -m pip install --upgrade pip

Boltz installation failed. See ChimeraX Log for details
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