LTX-2.5 (22B) on 20 GB of VRAM
Not at full quality. The 16-bit and 8-bit files are too big for 20 GB; the largest that fits is Q4_K_M (15.1 GB). The July 2026 LTX, with a custom Gemma 4 12B text encoder. GGUF sizes differ a lot between uploaders because they mix precisions differently; figures here use realrebelai's distilled files.
Q4_K_M (15.1 GB) fits with only 0.1 GB to spare (about 19.9 GB of 20 GB). Quality: good; some loss in fine detail and text. For better quality, Q5_K_M (16.8 GB) also runs, with about 1.6 GB spilling into system RAM - a little slower, still practical.
01What to download
| Part | File | Folder | Size | |
|---|---|---|---|---|
| Model | LTX-2.5-Distilled-Q4_K_M.gguf Q4_K_M · realrebelai/LTX-2.5_GGUFs | models/unet | 15.1 GB | Download → |
| Text encoder | gemma4-12b-with-proj-ltx-2.5-comfy-int8-convrot.safetensors Gemma 4 12B + LTX projection INT8 (convrot) · Lightricks/LTX-2.5 | models/text_encoders | 15.4 GB | Download → |
| VAE | ltx-2.5-video-vae-bf16.safetensors LTX-2.5 video VAE (DiffVAE) BF16 · Lightricks/LTX-2.5 | models/vae | 1.5 GB | Download → |
| Also needed | ltx-2.5-audio-vae-bf16.safetensors LTX-2.5 audio VAE + vocoder BF16 · Lightricks/LTX-2.5 | models/vae | 0.4 GB | Download → |
| Total download · keep about the same free on disk | 32.3 GB | |||
Alternatives: Gemma 4 12B + LTX projection BF16 (26.3 GB). Only for some workflows: LTX-2.5 latent spatial upscaler x2 (1.0 GB, official two-stage template); Gemma 4 E2B INT8 (prompt enhancer, optional) (5.2 GB, only if prompt enhancer enabled). Sizes from Hugging Face, 2026-10-01.
System RAM: 48 GB or more. These files take about 32.3 GB of RAM while loaded, 38.3 GB with Windows and ComfyUI. What happens with less. calculated
02Every file, on 20 GB
| File | Size | Needed | On this card | Quality | Download |
|---|---|---|---|---|---|
| 16-bit SAFETENSORS · Lightricks | 42.0 GB | 46.8 GB | 26.8 GB too big | the original weights | Hugging Face → |
| Q8_0 GGUF · realrebelai | 23.6 GB | 28.4 GB | 8.4 GB too big | practically identical to the original | Hugging Face → |
| Q6_K GGUF · realrebelai | 18.7 GB | 23.5 GB | 3.5 GB too big | very close to the original | Hugging Face → |
| Q5_K_M GGUF · realrebelai | 16.8 GB | 21.6 GB | spills 1.6 GB | close; small differences in fine detail | Hugging Face → |
| Q4_K_M ← GGUF · realrebelai | 15.1 GB | 19.9 GB | fits · 0.1 GB spare | good; some loss in fine detail and text | Hugging Face → |
| Q3_K_M GGUF · realrebelai | 11.5 GB | 16.3 GB | fits · 3.7 GB spare | noticeable loss of detail | Hugging Face → |
| Q2_K GGUF · realrebelai | 8.8 GB | 13.6 GB | fits · 6.4 GB spare | heavy loss; a last resort | Hugging Face → |
“Needed” adds 4 GB of working memory for LTX-2.5 and a 0.8 GB reserve. Sizes 2026-10-01.