Can the RX 9070 XT 16 GB run FLUX.2 [klein] 9B?
Download FP8 (9.4 GB). With the model's working memory it needs about 11.7 GB, leaving 4.3 GB spare on 16 GB. Quality: practically identical to the original.
01What to download
| Part | File | Folder | Size | |
|---|---|---|---|---|
| Model | flux-2-klein-9b-fp8.safetensors FP8 · black-forest-labs/FLUX.2-klein-9b-fp8 | models/diffusion_models | 9.4 GB | Download → |
| Text encoder | qwen_3_8b_fp8mixed.safetensors Qwen3 8B FP8 · Comfy-Org/flux2-klein-9B | models/text_encoders | 8.7 GB | Download → |
| VAE | flux2-vae.safetensors FLUX.2 VAE · Comfy-Org/flux2-dev | models/vae | 0.3 GB | Download → |
| Total download · keep about the same free on disk | 18.4 GB | |||
Alternatives: Qwen3 8B BF16 (16.4 GB). The 16-bit text encoder is a little more faithful; the smaller one is chosen here because it loads faster and needs less RAM. Sizes read from Hugging Face (2026-09-25). “Download” links start the file directly; the file name links are the same files the official ComfyUI workflows use.
System RAM: 32 GB or more. ComfyUI keeps the model file, the text encoder and the VAE in system RAM and moves them to the GPU as needed. With this set of files that is about 18.4 GB, plus roughly 6 GB for Windows, ComfyUI and a browser: 24.4 GB in total. With less RAM it still runs, but Windows starts swapping to disk and loading gets very slow. calculated
02Every FLUX.2 klein 9B file on 16 GB
| File | Size | Needed | On this card | Quality | Download |
|---|---|---|---|---|---|
| 16-bit SAFETENSORS · black-forest-labs | 18.2 GB | 20.5 GB | 4.5 GB too big | the original weights | Hugging Face → |
| FP8 ← SAFETENSORS · black-forest-labs | 9.4 GB | 11.7 GB | fits · 4.3 GB spare | practically identical to the original | Hugging Face → |
| Q8_0 GGUF · unsloth | 10.0 GB | 12.3 GB | fits · 3.7 GB spare | practically identical to the original | Hugging Face → |
| Q6_K GGUF · unsloth | 7.9 GB | 10.2 GB | fits · 5.8 GB spare | very close to the original | Hugging Face → |
| Q5_K_M GGUF · unsloth | 7.0 GB | 9.3 GB | fits · 6.7 GB spare | close; small differences in fine detail | Hugging Face → |
| Q4_K_M GGUF · unsloth | 5.9 GB | 8.2 GB | fits · 7.8 GB spare | good; some loss in fine detail and text | Hugging Face → |
| Q3_K_M GGUF · unsloth | 4.8 GB | 7.1 GB | fits · 8.9 GB spare | noticeable loss of detail | Hugging Face → |
| Q2_K GGUF · unsloth | 4.0 GB | 6.3 GB | fits · 9.7 GB spare | heavy loss; a last resort | Hugging Face → |
Sizes from the Hugging Face file listing, read 2026-09-25. “Needed” = file + 1.5 GB working memory for this model + 0.8 GB kept free for the system.
03The text encoder
Qwen3 8B: 16.4 GB as 16-bit, 8.7 GB as FP8. ComfyUI encodes the prompt first and can push the encoder out of VRAM before sampling, so it does not have to fit together with the model. On 16 GB the FP8 encoder fits on its own, so prompt encoding stays fast.
04About this GPU
ComfyUI supports AMD GPUs on Windows officially since v0.7.0 (January 2026), through ROCm. Memory works the same as on NVIDIA, so the fit verdicts apply. Some custom nodes are NVIDIA-only. RX 9000 (RDNA 4) GPUs have FP8 hardware, and ComfyUI computes FP8 natively on them with PyTorch 2.7+ and ROCm 6.4+.
RX 9070 XT 16 GB: 16 GB GDDR6 · 256-bit · 640 GB/s · RDNA 4. Everything that runs on the RX 9070 XT 16 GB →
05What more VRAM would change
Nothing to gain for this model: the RX 9070 XT 16 GB already runs a top-quality file entirely in VRAM. More memory would only help with bigger images, longer clips or several models at once.
06Measured and reported results
Nobody has sent measured numbers for this pair yet. If you run FLUX.2 klein 9B on a RX 9070 XT 16 GB, send your time per image and peak VRAM and it will appear here, credited.
07Questions
How much VRAM does FLUX.2 klein 9B need?
Around 6.3 GB with the smallest file (Q2_K) and 11.7 GB with an 8-bit file (FP8), counting working memory and a small system reserve. The full 16-bit file needs about 20.5 GB.
Which FLUX.2 klein 9B file should I download for the RX 9070 XT 16 GB?
FP8 (9.4 GB) from black-forest-labs/FLUX.2-klein-9b-fp8.
Is FP8 faster than GGUF on the RX 9070 XT 16 GB?
It can be. This GPU has FP8 hardware, and ComfyUI computes FP8 natively for files made for it (Comfy-Org's fp8_scaled files), or for any FP8 file with the --fast fp8_matrix_mult option. GGUF files are unpacked on the fly, which costs some speed.
How much do I need to download for FLUX.2 klein 9B on the RX 9070 XT 16 GB?
About 18.4 GB for the model file, text encoder and VAE listed on this page, and the same again free on disk. With a 16 GB card, 32 GB of system RAM or more is recommended.