deepspeedai / deepspeedai/DeepSpeed

Some question of gradient accumulation

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Description

engine.backward(loss)
engine.step()

Question 1: When using DeepSpeed, before calling engine.backward(loss), do I need to manually divide the loss by the gradient accumulation steps, or does DeepSpeed handle this scaling internally during backward propagation?

Question 2: At the end of an epoch, if the remaining batch does not reach the full gradient accumulation steps (e.g., only 2 steps instead of the configured 4), will DeepSpeed’s model.step() automatically handle this incomplete accumulation, or do I need to manually trigger gradient updates?

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Research direction

Start by tracing the DeepSpeed training entry points represented by engine.backward(loss) and engine.step(). Check how configured gradient accumulation affects loss scaling and an incomplete final accumulation, then document the confirmed behavior and required caller actions for both questions.

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Assessment

Tech stack
python
Domain
distributed-systems, machine-learning
Issue type
Documentation
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
25/100

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