Can the RTX 4090 24 GB run Illustrious XL / Pony (SDXL anime)?
Download 16-bit (6.9 GB). With the model's working memory it needs about 7.1 GB, leaving 16.9 GB spare on 24 GB. Quality: the original weights.
01What to download
| Part | File | Folder | Size | |
|---|---|---|---|---|
| Checkpoint | Illustrious-XL-v0.1.safetensors 16-bit · OnomaAIResearch/Illustrious-xl-early-release-v0 | models/checkpoints | 6.9 GB | Download → |
| Total download · keep about the same free on disk | 6.9 GB | |||
One file: the checkpoint already contains the text encoders and the VAE. 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: 16 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 6.9 GB, plus roughly 6 GB for Windows, ComfyUI and a browser: 12.9 GB in total. With less RAM it still runs, but Windows starts swapping to disk and loading gets very slow. calculated
02Every Illustrious / Pony file on 24 GB
| File | Size | Needed | On this card | Quality | Download |
|---|---|---|---|---|---|
| 16-bit ← SAFETENSORS · OnomaAIResearch | 6.9 GB | 7.1 GB | fits · 16.9 GB spare | the original weights | Hugging Face → |
| FP8 SAFETENSORS · calcuis | 3.5 GB | 5.5 GB | fits · 18.5 GB spare | practically identical to the original | Hugging Face → |
| Q8_0 GGUF · calcuis | 2.7 GB | 4.7 GB | fits · 19.3 GB spare | practically identical to the original | Hugging Face → |
| Q6_K GGUF · calcuis | 2.1 GB | 4.1 GB | fits · 19.9 GB spare | very close to the original | Hugging Face → |
| Q5_K_M GGUF · calcuis | 1.8 GB | 3.8 GB | fits · 20.2 GB spare | close; small differences in fine detail | Hugging Face → |
| Q4_K_M GGUF · calcuis | 1.5 GB | 3.5 GB | fits · 20.5 GB spare | good; some loss in fine detail and text | Hugging Face → |
| Q3_K_M GGUF · calcuis | 1.2 GB | 3.2 GB | fits · 20.8 GB spare | noticeable loss of detail | Hugging Face → |
| Q2_K GGUF · calcuis | 0.9 GB | 2.9 GB | fits · 21.1 GB spare | heavy loss; a last resort | Hugging Face → |
Sizes from the Hugging Face file listing, read 2026-09-25. “Needed” = file + 1.2 GB working memory for this model + 0.8 GB kept free for the system. The 6.94 GB checkpoint holds the UNet plus text encoders and VAE; only the UNet (about 5.1 GB) sits in VRAM while sampling. The GGUF and FP8 files from calcuis contain the UNet only.
03The text encoder
The text encoder is inside the checkpoint, so there is nothing extra to download.
04About this GPU
The RTX 4090 24 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.)
RTX 4090 24 GB: 24 GB GDDR6X · 384-bit · 1008 GB/s · Ada Lovelace. Everything that runs on the RTX 4090 24 GB →
05What more VRAM would change
Nothing to gain for this model: the RTX 4090 24 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.
What changes from the RTX 4090 24 GB to the RTX 5090 32 GB →
06Measured and reported results
| Label | Setup | Result | Peak VRAM | Date | Source |
|---|---|---|---|---|---|
| reported | Illustrious-XL-v2.0 · 1024x1024 “NVIDIA RTX 4090 | 7.00it/s | 0.14s/it | CUDA 12.9 | ComfyUI (Unknown) | Windows 11 24H2” Community speed list; ComfyUI, Euler/Normal, CFG 8, square 1:1, batch speed only (no per-image time); date = list last-updated date; SDXL 1024px section | 0.14 s/it | — | 2025-11-29 | huggingface.co → |
Reported results are other people's numbers, copied as published, with a link. Settings, drivers and ComfyUI versions differ, so compare them with care. Send yours.
07Questions
How much VRAM does Illustrious / Pony need?
Around 2.9 GB with the smallest file (Q2_K) and 5.5 GB with an 8-bit file (FP8), counting working memory and a small system reserve. The full 16-bit file needs about 7.1 GB.
Which Illustrious / Pony file should I download for the RTX 4090 24 GB?
16-bit (6.9 GB) from OnomaAIResearch/Illustrious-xl-early-release-v0.
Is FP8 faster than GGUF on the RTX 4090 24 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 Illustrious / Pony on the RTX 4090 24 GB?
About 6.9 GB for the model file, text encoder and VAE listed on this page, and the same again free on disk. With a 24 GB card, 16 GB of system RAM or more is recommended.