FLUX Model Download Reference for ComfyUI on ROCm

Quick reference for downloading FLUX models for local ComfyUI inference on AMD ROCm (no HuggingFace login).

Official FLUX Models from Black Forest Labs

Model	Params	Open?	Size (FP16)
FLUX.1 [dev]	12B	✅	~23 GB
FLUX.1 [schnell]	12B	✅	~23 GB
FLUX.1 [pro]	?	❌ (API only)	—
FLUX.2 [dev]	?	✅	16.9 GB
FLUX.2 [klein-9B]	9B	✅	16.9 GB
FLUX.2 [klein-4B]	4B	✅	~3.7 GB (Q4)

The klein variants are faster, smaller variants of FLUX.2.

GGUF Quantizations (No Auth Required)

When HuggingFace requires login (gated models), use community GGUF repos:

Unsloth GGUF repo (unsloth/FLUX.2-klein-9B-GGUF):

flux-2-klein-9b-Q4_K_S.gguf — 5.43 GB ← best balance for most GPUs
flux-2-klein-9b-Q4_K_M.gguf — 5.50 GB
flux-2-klein-9b-Q4_0.gguf — 5.23 GB
flux-2-klein-9b-Q5_K_S.gguf — 6.46 GB
flux-2-klein-9b-Q8_0.gguf — 9.29 GB

Leejet GGUF repo (leejet/FLUX.2-klein-9B-GGUF):

flux-2-klein-9b-Q4_0.gguf — 5.23 GB
flux-2-klein-9b-Q8_0.gguf — 9.29 GB (fewer options than unsloth)

FLUX.1-dev GGUF repo (city96/FLUX.1-dev-gguf or similar):

flux1-dev-Q4_K_S.gguf — 6.4 GB

Authentication Barriers

Source	Requires Auth?	Notes
`black-forest-labs/*` (HuggingFace)	✅ Yes (gated)	Must login + accept license
`unsloth/*-GGUF`	❌ No	Community quant, direct download
`leejet/*-GGUF`	❌ No	Community quant, direct download
`civitai.com`	❌ No (most)	Use `api/download/models/<id>?type=Model&format=SafeTensor`
`modelscope.cn`	❌ No	China mirror, works for FLUX files

If a download returns a tiny (~140 byte) file: The request was redirected to a login page or error page. The HTML response is ~140 bytes. Always verify the downloaded file size matches expectations.

Required Auxiliary Models

Shared VAE (all FLUX models):

File	Size	Purpose	Where to get (no auth)
`ae.safetensors` (VAE)	319 MB	Image decoder	modelscope.cn (HuggingFace gated)

Text encoders are NOT shared:

FLUX.1 (dev / schnell): CLIP-L + T5XXL → clip_l.safetensors + t5xxl_fp8_e4m3fn.safetensors
FLUX.2-klein-9B: Uses 8B Qwen3 text embedder (NOT CLIP-L / T5XXL). Incompatible with ComfyUI's DualCLIPLoaderGGUF. Attempting to run FLUX.2 with FLUX.1 encoders produces RuntimeError: mat1 and mat2 shapes cannot be multiplied (512x4096 and 12288x4096). Use diffusers Flux2KleinPipeline or find ComfyUI Qwen3 nodes.

File	Size	Purpose	Where to get	Required for
`clip_l.safetensors`	235 MB	CLIP text encoder	civitai or modelscope	FLUX.1 only
`t5xxl_fp8_e4m3fn.safetensors`	4.9 GB	T5 XXL text encoder	civitai or modelscope	FLUX.1 only

Working VAE download URLs (no-auth)

# Modelscope (verified working, no auth)
curl -L -o ae.safetensors \
  "https://www.modelscope.cn/models/AI-ModelScope/FLUX.1-dev/resolve/master/ae.safetensors"

# Direct HuggingFace (REQUIRES login for BFL repos)
# curl -L -o ae.safetensors \
#   "https://huggingface.co/black-forest-labs/FLUX.1-schnell/resolve/main/ae.safetensors"
# → Will fail with 401, producing a ~140 byte HTML error page

Background Download Pattern

For multi-GB model downloads from inside a Proxmox LXC, use nohup to survive SSH/session timeouts:

pct exec 204 -- bash -c '
  cd /opt/ComfyUI/models/unet
  nohup bash -c "curl -L -o flux-2-klein-9b-Q4_K_S.gguf \\"
    https://huggingface.co/unsloth/FLUX.2-klein-9B-GGUF/resolve/main/flux-2-klein-9b-Q4_K_S.gguf \\"
    > /tmp/flux2_download.log 2>&1" &
'

Verify ongoing download:

pct exec 204 -- bash -c 'ls -lh /opt/ComfyUI/models/unet/flux-2-klein-9b-Q4_K_S.gguf'
pct exec 204 -- bash -c 'tail -3 /tmp/flux2_download.log'

ComfyUI Model Paths

/opt/ComfyUI/models/
├── unet/           # GGUF diffusion models (FLUX, SDXL, etc.)
│   └── flux-2-klein-9b-Q4_K_S.gguf
├── clip/           # Text encoders
│   ├── clip_l.safetensors
│   └── t5xxl_fp8_e4m3fn.safetensors
├── vae/            # Image decoders
│   └── ae.safetensors
└── checkpoints/    # Full safetensors models

ComfyUI + ROCm + GGUF Verification

After downloading, verify ComfyUI can load the model:

# Start ComfyUI
pct exec 204 -- bash -c 'cd /opt/ComfyUI && python3 main.py --listen 0.0.0.0 --port 8188'

# Check API responds
curl http://10.0.20.91:8188/system_stats

# The first run will compile shaders; monitor /tmp/comfyui.log
pct exec 204 -- bash -c 'tail -20 /tmp/comfyui.log'

Errors and Fixes

Error	Cause	Fix
`hipErrorNoBinaryForGpu`	PyTorch ROCm wheel mismatch with host ROCm	Downgrade/upgrade PyTorch wheel: `pip install torch --index-url https://download.pytorch.org/whl/rocm6.2`
Downloaded file is ~140 bytes	Gated model, no auth token	Switch to unsloth/leejet GGUF repos or modelscope
Downloaded file is 6+ GB for VAE	Wrong CivitAI URL (model page, not direct download)	Use correct `api/download/models/<id>?type=Model&format=SafeTensor` URL
`curl` times out during download	Paramiko SSH timeout	Use `nohup` + background; poll file size separately

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