deepspeedai / deepspeedai/DeepSpeed

[REQUEST] Mixed dtype for model parameters

Open
#4,689 2 comments 3 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

enhancement
Dominant language
Python
Stars
43.1k
Forks
5k
Avg merge
4d 15h
Merged PRs (30d)
112

Description

Is your feature request related to a problem? Please describe.
Is it possible to support model of irregular dtypes? For example, a large multimodal LLM might have a vision encoder that is of dtype=float32 and its LLM part in dtype=bfloat16. This will be particularly helpful since some customized vision models (e.g., MinkowskiEngine) don't support float16/bfloat16.

Describe the solution you'd like
Have a flag (e.g., dont_change_dtype) in DeepSpeedEngine to allow loading a nn.Module model without modifying its dtypes of various parameters (e.g., some params might be float32, while some are bfloat16)

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start at the DeepSpeedEngine model-loading path and inspect how it changes the dtypes of parameters in a torch.nn.Module. The requested behavior is a flag that preserves mixed parameter dtypes, including float32 and bfloat16; done means models with irregular dtypes can load without those dtypes being modified.

Written by the indexing model from the issue text.

Assessment

Tech stack
python, pytorch
Domain
machine-learning
Issue type
Feature
Difficulty
5/5
Estimated time
Over a week
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
35/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.