Can the RTX 5090 32 GB run LTX-2 (19B)?
Yes. Q8_0 fits on the RTX 5090 32 GB with 6.8 GB to spare.
Q8_0 (20.4 GB) needs about 25.2 GB in use, so 6.8 GB of the 32 GB stays free: room for a larger image, a LoRA or a ControlNet.
01What to download
| Part | File | Folder | Size | |
|---|---|---|---|---|
| Model | ltx-2-19b-dev-Q8_0.gguf Q8_0 · unsloth/LTX-2-GGUF | models/unet | 20.4 GB | Download → |
| Text encoder | gemma_3_12B_it_fp4_mixed.safetensors Gemma 3 12B FP4 mixed · Comfy-Org/ltx-2 | models/text_encoders | 9.4 GB | Download → |
| VAE | ltx-2-19b-dev_video_vae.safetensors LTX-2 video VAE · unsloth/LTX-2-GGUF | models/vae | 2.4 GB | Download → |
| Also needed | ltx-2-19b-dev_audio_vae.safetensors LTX-2 audio VAE · unsloth/LTX-2-GGUF | models/vae | 0.2 GB | Download → |
| Also needed | ltx-2-19b-dev_embeddings_connectors.safetensors LTX-2 text embeddings connectors (projection) · unsloth/LTX-2-GGUF | models/text_encoders | 2.9 GB | Download → |
| Total download · keep about the same free on disk | 35.4 GB | |||
Alternatives: Gemma 3 12B FP8 (scaled) (13.2 GB); Gemma 3 12B BF16 (24.4 GB). Only for some workflows: LTX-2 spatial upscaler x2 (1.0 GB, official two-stage template). Sizes from Hugging Face, 2026-10-01.
System RAM: 48 GB or more. These files take about 35.4 GB of RAM while loaded, 41.4 GB with Windows and ComfyUI. What happens with less. calculated
02Every LTX-2 file on 32 GB
| File | Size | Needed | On this card | Quality | Download |
|---|---|---|---|---|---|
| 16-bit GGUF · unsloth | 37.8 GB | 42.6 GB | 10.6 GB too big | the original weights | Hugging Face → |
| Q8_0 ← GGUF · unsloth | 20.4 GB | 25.2 GB | fits · 6.8 GB spare | practically identical to the original | Hugging Face → |
| Q6_K GGUF · unsloth | 16.0 GB | 20.8 GB | fits · 11.2 GB spare | very close to the original | Hugging Face → |
| Q5_K_M GGUF · unsloth | 14.3 GB | 19.1 GB | fits · 12.9 GB spare | close; small differences in fine detail | Hugging Face → |
| Q4_K_M GGUF · unsloth | 12.8 GB | 17.6 GB | fits · 14.4 GB spare | good; some loss in fine detail and text | Hugging Face → |
| Q3_K_M GGUF · unsloth | 10.1 GB | 14.9 GB | fits · 17.1 GB spare | noticeable loss of detail | Hugging Face → |
| Q2_K GGUF · unsloth | 8.1 GB | 12.9 GB | fits · 19.1 GB spare | heavy loss; a last resort | Hugging Face → |
“Needed” adds 4 GB of working memory for LTX-2 and a 0.8 GB reserve. Sizes 2026-10-01.
03Measured and reported results
| Label | Setup | Result | Peak VRAM | Date | Source |
|---|---|---|---|---|---|
| reported | LTX-2 19B NVFP4 · 720p “generating 143 frames at 720p takes about 66 seconds end‑to‑end in ComfyUI” Issue says this is ~30-40% slower than NVIDIA's expected 40-45 s; steps not stated | 66 s / clip (143 frames) | — | 2026-01-08 | github.com → |
Other people's numbers are copied as published, with a link. Send yours.
04About the RTX 5090 32 GB
The RTX 5090 32 GB is a Blackwell GPU with FP8 and FP4 hardware: ComfyUI computes Comfy-Org's FP8 files natively here, and NVFP4 files (where a model offers them) are faster still.
32 GB GDDR7 · 512-bit · 1792 GB/s · Blackwell. Everything that runs on it →
05Questions
How much VRAM does LTX-2 need?
Around 12.9 GB with the smallest file (Q2_K) and 25.2 GB with an 8-bit file (Q8_0). The full 16-bit file needs about 42.6 GB.
Which LTX-2 file should I download for the RTX 5090 32 GB?
Q8_0 (20.4 GB) from unsloth/LTX-2-GGUF. Load it with Unet Loader (GGUF) from the ComfyUI-GGUF node pack.
How much do I need to download for LTX-2 on the RTX 5090 32 GB?
35.4 GB: ltx-2-19b-dev-Q8_0.gguf, gemma_3_12B_it_fp4_mixed.safetensors, ltx-2-19b-dev_video_vae.safetensors, ltx-2-19b-dev_audio_vae.safetensors, ltx-2-19b-dev_embeddings_connectors.safetensors.