Can the RTX 4090 Laptop 16 GB run HiDream-I1 (Full)?
Not at full quality. The 16-bit and 8-bit files are too big for the RTX 4090 Laptop 16 GB; the largest that fits is Q5_K_M (13.0 GB).
Q5_K_M (13.0 GB) fits with only 0.2 GB to spare (about 15.8 GB of 16 GB). Quality: close; small differences in fine detail. For better quality, Q6_K (14.7 GB) also runs, with about 1.5 GB spilling into system RAM - a little slower, still practical.
Also try the FP8 file (17.1 GB) on this GPU. It does not fit entirely, but a current ComfyUI streams the overflow from RAM and native 8-bit files often beat a small GGUF that does fit. Dynamic VRAM →
01What to download
| Part | File | Folder | Size | |
|---|---|---|---|---|
| Model | hidream-i1-full-Q5_K_M.gguf Q5_K_M · city96/HiDream-I1-Full-gguf | models/unet | 13.0 GB | Download → |
| Text encoder | t5xxl_fp8_e4m3fn_scaled.safetensors T5-XXL FP8 scaled · Comfy-Org/HiDream-I1_ComfyUI | models/text_encoders | 5.2 GB | Download → |
| Text encoder | clip_l_hidream.safetensors CLIP-L (HiDream) · Comfy-Org/HiDream-I1_ComfyUI | models/text_encoders | 0.2 GB | Download → |
| Text encoder | clip_g_hidream.safetensors CLIP-G (HiDream) · Comfy-Org/HiDream-I1_ComfyUI | models/text_encoders | 1.4 GB | Download → |
| Text encoder | llama_3.1_8b_instruct_fp8_scaled.safetensors Llama 3.1 8B Instruct FP8 · Comfy-Org/HiDream-I1_ComfyUI | models/text_encoders | 9.1 GB | Download → |
| VAE | ae.safetensors FLUX.1 VAE (ae) · Comfy-Org/HiDream-I1_ComfyUI | models/vae | 0.3 GB | Download → |
| Total download · keep about the same free on disk | 29.2 GB | |||
Alternatives: T5-XXL FP16 (9.8 GB). Sizes from Hugging Face, 2026-10-01.
System RAM: 48 GB or more. These files take about 29.2 GB of RAM while loaded, 35.2 GB with Windows and ComfyUI. What happens with less. calculated
02Every HiDream-I1 Full file on 16 GB
| File | Size | Needed | On this card | Quality | Download |
|---|---|---|---|---|---|
| 16-bit SAFETENSORS · Comfy-Org | 34.2 GB | 37.0 GB | 21.0 GB too big | the original weights | Hugging Face → |
| FP8 SAFETENSORS · Comfy-Org | 17.1 GB | 19.9 GB | 3.9 GB too big | practically identical to the original | Hugging Face → |
| Q8_0 GGUF · city96 | 18.7 GB | 21.5 GB | 5.5 GB too big | practically identical to the original | Hugging Face → |
| Q6_K GGUF · city96 | 14.7 GB | 17.5 GB | spills 1.5 GB | very close to the original | Hugging Face → |
| Q5_K_M ← GGUF · city96 | 13.0 GB | 15.8 GB | fits · 0.2 GB spare | close; small differences in fine detail | Hugging Face → |
| Q4_K_M GGUF · city96 | 11.5 GB | 14.3 GB | fits · 1.7 GB spare | good; some loss in fine detail and text | Hugging Face → |
| Q3_K_M GGUF · city96 | 8.8 GB | 11.6 GB | fits · 4.4 GB spare | noticeable loss of detail | Hugging Face → |
| Q2_K GGUF · city96 | 6.6 GB | 9.4 GB | fits · 6.6 GB spare | heavy loss; a last resort | Hugging Face → |
“Needed” adds 2 GB of working memory for HiDream-I1 Full and a 0.8 GB reserve. Sizes 2026-10-01.
03The text encoder
At 15.9 GB even the smallest CLIP-L + CLIP-G + T5-XXL + Llama 3.1 8B file is too big for 16 GB, so it runs from system RAM. That slows down reading the prompt, not the picture. Sizes: FP8 15.9 GB (all four together: CLIP-L 0.25 + CLIP-G 1.39 + T5-XXL FP8 5.16 + Llama 3.1 8B FP8 9.08 GB). Why the encoder does not count against VRAM →
04Measured and reported results
Nobody has sent measured numbers for this pair yet. If you run HiDream-I1 Full on a RTX 4090 Laptop 16 GB, send your time per image and peak VRAM and it will appear here, credited.
05With more VRAM
With 20 GB you could run HiDream-I1 Full at 8-bit or better (FP8, 17.1 GB) with no offloading.
06About the RTX 4090 Laptop 16 GB
The RTX 4090 Laptop 16 GB is an Ada Lovelace GPU with hardware FP8, so ComfyUI can compute Comfy-Org's FP8 files natively: small and fast. (Plain FP8 files use FP8 maths with the --fast fp8_matrix_mult option.) As a laptop GPU it runs at a lower power limit than desktop cards (80–150 W depending on the laptop). The memory verdicts are the same; speed depends heavily on how much power the laptop maker allows.
16 GB GDDR6 · 256-bit · Ada Lovelace · 80–150 W. Everything that runs on it →
07Questions
How much VRAM does HiDream-I1 Full need?
Around 9.4 GB with the smallest file (Q2_K) and 19.9 GB with an 8-bit file (FP8). The full 16-bit file needs about 37.0 GB.
Which HiDream-I1 Full file should I download for the RTX 4090 Laptop 16 GB?
Q5_K_M (13.0 GB) from city96/HiDream-I1-Full-gguf. Load it with Unet Loader (GGUF) from the ComfyUI-GGUF node pack.
FP8 or Q8_0 for HiDream-I1 Full on the RTX 4090 Laptop 16 GB?
FP8 (17.1 GB): the RTX 4090 Laptop 16 GB computes it natively, while Q8_0 (18.7 GB) is unpacked on the fly.
How much do I need to download for HiDream-I1 Full on the RTX 4090 Laptop 16 GB?
29.2 GB: hidream-i1-full-Q5_K_M.gguf, t5xxl_fp8_e4m3fn_scaled.safetensors, clip_l_hidream.safetensors, clip_g_hidream.safetensors, llama_3.1_8b_instruct_fp8_scaled.safetensors, ae.safetensors.