MiniMax H3 troubleshooting
Bottom line: Match the failure stage first; the five symptom paths below give one targeted check and a rollback-safe test before you change anything else.
Community fixes may not apply to every environment.
Start with the symptom, not random flags
| Symptom | Likely area | First check | Guide section |
|---|---|---|---|
| OOM before sampling | Text encoder or model load | Encoder precision, free VRAM, model handoff | Model handoff |
| Each step becomes slower | DynamicVRAM, RAM leak, offload thrashing | RAM/swap growth and per-step log times | Runaway step time |
| Whole machine freezes | Pinned memory or exhausted RAM/swap | System memory and pinned-memory flags | System freeze |
| Model not found | Wrong folder or stale loader list | File path and exact loader filename | Models and nodes |
hipMemAddressReserve error | AMD DynamicVRAM/ROCm interaction | ROCm, Torch, Triton and launch flags | AMD and ROCm |
Per-step time keeps increasing
An RTX 4070 Ti 12GB, 64GB RAM, Windows and ComfyUI 0.30.1 community report described a GGUF run starting around 18 seconds per step and eventually exceeding 400 seconds per step. The author associated the behavior with DynamicVRAM and a GGUF RAM leak.
Community-reported test flags
--disable-dynamic-vram --disable-pinned-memory
Before testing, save the original launch command. Compare per-step time, system RAM and swap with only this change, then revert if performance gets worse.
If steps are simply slow rather than getting slower, that is a different problem with a different fix. Our measurements of eight cache nodes show which ones cut run time on a 12GB card, and how to check whether the one you installed is doing anything at all.
Reported environment: RTX 4070 Ti 12GB, 64GB RAM, Windows, ComfyUI 0.30.1, GGUF.
This is not a universal GGUF or DynamicVRAM diagnosis.
MiniMax H3 freezes the whole PC
One Ubuntu report linked a full-system lock to pinned-memory pressure rather than a simple CUDA OOM. The author's stable launch included the following flags:
--disable-pinned-memory
--disable-smart-memory
--cache-none
--fast-disk
Do not paste the full set blindly. Test pinned memory first, monitor RAM and swap, and keep remote access or a local recovery path available when reproducing a hard-lock report.
Reported environment: RTX 3060 12GB, 32GB RAM, Ubuntu 24.04, ComfyUI 0.30.0.
The same author reported a later 480p/five-second native-audio run peaking near 7.4GB system RAM and 6.2GB VRAM after changing the launch path.
OOM when the diffusion model starts
A 16GB RTX 5070 Ti report found that the text encoder remained allocated when
the diffusion model loaded. The author inserted a KJNodes VRAM_Debug barrier
and forced cache and garbage collection before the handoff.
- Confirm whether the OOM appears after text encoding but before the first diffusion step.
- Log free VRAM immediately before both model loads.
- Test an explicit unload or cleanup barrier at the handoff.
- Keep the workflow copy so the cleanup node can be removed if it causes a new error.
Community workaround: KJNodes VRAM_Debug with empty_cache and
gc_collect at the model boundary.
Model not found or missing nodes
Diffusion model
ComfyUI/models/diffusion_models/
Place the MiniMax H3 diffusion file here, then select its exact installed filename in the workflow loader.
Text encoder
ComfyUI/models/text_encoders/
Qwen3-VL encoder variants belong here. A workflow may reference a filename you did not download.
Video and audio VAE
ComfyUI/models/vae/
Keep video and audio VAE files distinct and match the nodes used by the chosen workflow.
Missing custom node
Open ComfyUI Manager, install the repository named by the missing node, restart ComfyUI, and reload the JSON. Do not install unrelated node packs at random.
Exact cache-node error:
AttributeError: module 'comfy.ldm.minimax.model' has no attribute 'time_shift_slope'
is not a missing base-model file. On this site's own bench,
comfyui-speed-minimaxH3 raised it on ComfyUI 0.31.0; the node author documents
testing on 0.30.0. Disable the node and prove the clean workflow first. Test
another ComfyUI version only in a separate, rollback-safe environment; one
failed run is not a universal compatibility verdict.
AMD hipMemAddressReserve or slower attention
An RX 7900 XT author reported DynamicVRAM failing with
hipMemAddressReserveand SageAttention v1 running slower, while another participant reported DynamicVRAM working with different flags and software. This is a real community conflict, not a settled fix.
- Record the exact ROCm, Torch, Triton and ComfyUI versions.
- Start with the author's known-running AOTriton path before adding attention replacements.
- A/B test DynamicVRAM with the same input, seed, frames and model files.
- Watch system RAM; some reports mention more than 40GB usage under offload.
Make every change reversible
Save baseline
Copy the workflow and launch command before changing anything.
Locate stage
Record the last completed node or log line and current RAM/VRAM.
Change one thing
One flag, model or workflow node per test keeps the result interpretable.
Keep evidence
Save logs and undo the change if it does not improve the exact symptom.
Common MiniMax H3 errors
Why do MiniMax H3 ComfyUI steps get slower after every step?
One RTX 4070 Ti 12GB community report described per-step time rising from about 18 seconds to more than 400 seconds with a GGUF workflow. The author associated it with DynamicVRAM and a RAM leak and reported improvement after disabling DynamicVRAM and pinned memory. Treat this as an environment-specific test, not a universal fix.
Why does MiniMax H3 ComfyUI freeze the whole PC on Ubuntu?
A community Ubuntu 24.04 report linked a full-system lock to pinned-memory pressure. The author stabilized that setup with flags disabling pinned and smart memory plus cache changes. Save your current launch command and test one flag at a time because the same flags may reduce performance elsewhere.
How do I fix MiniMax H3 OOM before the first diffusion step?
Check whether text encoding finishes before the OOM. Log free VRAM before the encoder and diffusion model loads, then test an explicit unload or cleanup barrier at the handoff on a copy of the workflow. A 16GB RTX 5070 Ti community report used KJNodes VRAM_Debug with empty_cache and gc_collect; this is an environment-specific workaround.
How do I fix "model not found" in MiniMax H3 ComfyUI?
Confirm that diffusion models are in models/diffusion_models, text encoders are in models/text_encoders, and video or audio VAEs are in models/vae. Then select the installed filenames in the loader nodes and restart ComfyUI if the file list is stale.
What causes hipMemAddressReserve in MiniMax H3 ComfyUI on AMD?
An RX 7900 XT community report tied the error to DynamicVRAM under one ROCm, Torch and Triton setup, while another user reported a working combination. Record the exact versions and A/B test DynamicVRAM from a clean copy; the conflict is not a universal diagnosis.
How do I fix “module 'comfy.ldm.minimax.model' has no attribute 'time_shift_slope'”?
On this site's ComfyUI 0.31.0 bench, the comfyui-speed-minimaxH3 cache node raised that error because the runtime hook was missing; its author documents testing on ComfyUI 0.30.0. Disable the node and confirm the clean workflow runs first. If you test 0.30.0, use a separate rollback-safe environment; this one failure does not prove the node fails on every version.