Comfy-Org / Comfy-Org/ComfyUI

Performance Regression & OOM in v0.6.0 compared to v0.5.1 (RTX 4080)

Open
#11,533 12 comments 2 reactions 0 assignees View on GitHub
Potential Bug
Dominant language
Python
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Avg merge
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Merged PRs (30d)
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Description

### Custom Node Testing

- [ ] I have tried disabling custom nodes and the issue persists (see [how to disable custom nodes](https://docs.comfy.org/troubleshooting/custom-node-issues#step-1%3A-test-with-all-custom-nodes-disabled) if you need help)

### Expected Behavior

Describe the bug
I am experiencing significant performance degradation and Out of Memory (OOM) issues after updating from v0.5.1 to v0.6.0. With the exact same workflow and settings, the behavior has changed drastically.
Comparison:
v0.5.1: Stable, no OOM. Performance was acceptable (approx. 700s for 10 images, ~70s/img).
v0.6.0: Frequent OOM. Even when it runs, it is much slower (approx. 400s for only 2 images, ~200s/img).
Environment:
GPU: NVIDIA RTX 4080 (16GB VRAM)
RAM: 128GB
Model: QwenEdit 2511 BF16
Weight Type: Loaded using fp8_e4m3 (f8_em4)
Workflow: Identical across both versions.
Additional Context:
I also noticed the following warning in the console which might be related to node logic or memory management:
WARNING: ProcessString.IS_CHANGED() got an unexpected keyword argument 'input_string'

### Actual Behavior

After upgrading from v0.5.1 to v0.6.0, I encountered a significant performance regression and frequent Out of Memory (OOM) issues using the same workflow and hardware (RTX 4080 16GB, 128GB RAM).
Comparison:
v0.5.1: Stable and efficient. 10 images were completed in about 700 seconds (~70s/img).
v0.6.0: Frequent OOM errors. When it does run, it is extremely slow, taking 400 seconds for just 2 images (~200s/img).
Technical Details:
Model: QwenEdit 2511 BF16
Weight type: fp8_e4m3
Console Warning: WARNING: ProcessString.IS_CHANGED() got an unexpected keyword argument 'input_string'
It seems like memory management or VRAM offloading logic has changed significantly in the new version, leading to much higher resource consumption.

### Steps to Reproduce

Update the environment to version 0.6.0.
Load a workflow using the QwenEdit 2511 BF16 model.
Set the model weight type to fp8_e4m3.
Run a batch generation (e.g., 2 or more images).
Monitor VRAM usage and generation time. Compare the results with version 0.5.1.
Check the console for the ProcessString.IS_CHANGED warning and observe the OOM crash during the sampling process.

### Debug Logs

```powershell
WARNING: ProcessString.IS_CHANGED() got an unexpected keyword argument 'input_string'
HTTP Request: POST https:///v1/chat/completions "HTTP/1.1 200 OK"
Requested to load WanVAE
Unloaded partially: 621.46 MB freed, 10947.53 MB remains loaded, 252.01 MB buffer reserved, lowvram patches: 596
loaded completely; 291.73 MB usable, 242.03 MB loaded, full load: True
Requested to load QwenImageTEModel_
Unloaded partially: 6626.12 MB freed, 4321.41 MB remains loaded, 378.09 MB buffer reserved, lowvram patches: 760
loaded completely; 8875.12 MB usable, 7910.29 MB loaded, full load: True
Unloaded partially: 1674.54 MB freed, 2646.86 MB remains loaded, 378.09 MB buffer reserved, lowvram patches: 791
loaded partially; 11821.09 MB usable, 11568.99 MB loaded, 7914.96 MB offloaded, 252.01 MB buffer reserved, lowvram patches: 0
100%|████████████████████████████████████████████████████████████████████████████████████| 8/8 [03:39<00:00, 27.47s/it]
loaded partially; 11821.09 MB usable, 11568.99 MB loaded, 7914.96 MB offloaded, 252.01 MB buffer reserved, lowvram patches: 0
12%|██████████▍ | 1/8 [02:19<16:19, 139.95s/it]
```

### Other

_No response_

Contributor guide

Open the contributing guide

Research direction

Start by reproducing the v0.5.1 versus v0.6.0 comparison with the QwenEdit 2511 BF16 workflow, fp8_e4m3 weights, and an RTX 4080. Check the ProcessString.IS_CHANGED warning alongside the VRAM and timing logs; done means identifying the regression and confirming that the same batch no longer OOMs or suffers the reported slowdown.

Written by the indexing model from the issue text.

Assessment

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

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