google-deepmind / google-deepmind/alphafold

bug: NAN in latest version of jax when using multimer+bfloat16

Open
#724 4 comments 0 reactions 0 assignees View on GitHub
Dominant language
Python
Stars
14.9k
Forks
2.9k
PR merge metrics
No merged PRs in 30d

Description

I think I tracked down the issue.

The issue comes from when the multimer model is run without templates. Zero features are appended to `msa_mask`. This creates a very large negative bias that bfloat16 can't seem to handle.

if you replace:
`bias = (1e9 * (msa_mask - 1.))[:, None, None, :]`
with:
`bias = (1e4 * (msa_mask - 1.))[:, None, None, :]`

No more NANS!

See:
https://github.com/deepmind/alphafold/blob/main/alphafold/model/modules.py#L764

Contributor guide

Open the contributing guide

Assessment

This issue has not been assessed yet.

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.