Skip to content

Checkpoint Loading Memory

Loading checkpoints can temporarily double memory usage because both old and new model states exist in memory.

Quick answer

Loading checkpoints can temporarily double memory usage because both old and new model states exist in memory.

Memory#checkpoint#loading#memory#safetensors#resume

What this failure is

Checkpoint Loading Memory is a Memory failure seen during ML training runs. Loading checkpoints can temporarily double memory usage because both old and new model states exist in memory. Common tags: Checkpoint, Loading, Memory, Safetensors.

Live diagnosis, no signup

Is this what broke your run? Paste your log.

You're reading about Checkpoint Loading Memory. Paste your own crash log or traceback below and get the real root cause for YOUR run, not this generic entry. No account, no card. Logs are masked at ingress and never saved to account history.

training_logs.txt
No log to hand? Try one:

3 free diagnoses/day

Want 14 days on the Scale plan?

Request an evaluation code. A verified workplace organization activates up to 50 diagnoses a day, alerts, history, and follow-up questions. No credit card or automatic subscription.

Evaluate one incident

Why it happens (the mechanism)

Old model in memory while loading new. Pickle deserialization creates copies. State dict not directly mapped to model. Loading on CPU then transferring to GPU uses both. Taken together, these mechanisms explain why the failure is reproducible, why it tends to surface on specific workloads or scales, and why generic mitigation attempts often fall short without addressing the underlying cause.

What you'll observe

  • OOM during checkpoint load
  • Memory spikes when loading checkpoint
  • Cannot resume from checkpoint

Common symptoms and what they mean

SymptomWhy it happens
CUDA OOM at checkpoint.load_state_dict()Old model in memory while loading new
Memory doubled during checkpoint loadingPickle deserialization creates copies
Loading checkpoint on different model architectureState dict not directly mapped to model

Which systems are affected

  • Resuming long training
  • Transfer learning from pretrained
  • Loading large model checkpoints

How to confirm this is the problem

Use this checklist to test the hypothesis against a small reproduction. No single line proves the root cause, so preserve the preceding events and compare one variable at a time.

  • Reproduce the failure from a clean checkpoint/seed: the symptom must appear without warm-up state from a previous run.
  • Verified signal present: CUDA OOM at checkpoint.load_state_dict()
  • Verified signal present: Memory doubled during checkpoint loading
  • Verified signal present: Loading checkpoint on different model architecture
  • A targeted fix from the "How to fix it" section eliminates or substantially reduces the symptom within one validation pass.

The fix and the prevention pattern

The root cause is on this page and stays free. A free account adds the exact remediation steps, saved history, and the fix on every entry in the encyclopedia.

Sign up free. Unlock the full analysis

No credit card. Daily allowance follows verified trust tier. Instant access.

Diagnose this failure in VS Code

Select the traceback or open the failed terminal, then run Denpex locally to see the initiating rank, collateral failures, exact fix, and verification command without uploading the log.

Install the free VS Code extension

Root cause

  • Old model in memory while loading new
  • Pickle deserialization creates copies
  • State dict not directly mapped to model
  • Loading on CPU then transferring to GPU uses both

The fix and how to prevent it

Evaluate Denpex on your own logs

Request a Scale evaluation code. A verified workplace organization activates 14 days with up to 50 diagnoses a day. Every account keeps its current diagnosis allowance and gets a verification path. No card or automatic subscription.

We send a single-use code tied to that address. Static provider and TLD rules do not reject valid addresses. Account trust determines the benefit after signup.

Don't just read the fix, diagnose your run

The encyclopedia tells you what went wrong. Denpex tells you what went wrong in YOUR training run. With your logs, your config, and your stack.