FLUX.1 Schnell VRAM Requirements
How much VRAM FLUX.1 schnell needs for local image generation, from 12 GB quantized setups to comfortable 24 GB GPUs.
FLUX.1 schnell is the fast, open-weight FLUX variant most builders test first. The practical question is simple: can your GPU load it without offloading half the pipeline to system RAM?
Quick answer
FLUX.1 schnell is a 12B parameter model, so the weights alone are large. For a normal local workflow, plan around a 24 GB GPU if you want a comfortable experience. That usually means FP8 or selective offload for supporting components rather than keeping every part of the pipeline in full precision on the GPU.
For quantized workflows, 12 GB can work, but it usually means NF4 or similar quantization, more careful ComfyUI settings, and less headroom for high resolutions or larger batches.
| Setup | Practical VRAM target | Best fit |
|---|---|---|
| Comfortable local workflow | 24 GB | RTX 4090, RTX 3090, L40S |
| FP8 / mixed precision | 16 GB | RTX 4080, RTX 4060 Ti 16GB |
| NF4 quantized | 12 GB | RTX 3060 12GB, RTX 4070 12GB |
| CPU offload | 8 GB | Testing only, slow |
What changes VRAM usage
Resolution matters. A 1024x1024 image is the common baseline, but larger canvases, hires fix workflows, ControlNet-style extras, and batching all raise memory use.
The text encoder also matters. Many low-VRAM guides focus only on the FLUX transformer weights, but the T5 encoder and VAE still need memory unless they are offloaded or loaded in reduced precision.
Recommended GPUs
If you are renting cloud GPUs, an RTX 4090 is usually the best price/performance choice for FLUX.1 schnell. It has enough VRAM for a practical production-style setup and is often far cheaper per hour than A100 or H100 instances.
If you are running locally, a 24 GB consumer GPU is the comfortable tier. A 12 GB card is viable for experimentation, but expect to use quantized checkpoints and more conservative settings.
Local vs cloud
| Goal | Recommendation |
|---|---|
| Cheapest local testing | 12 GB GPU with NF4 quantized workflow |
| Smooth local use | 24 GB GPU |
| Cheapest cloud generation | RTX 4090 community instance |
| Production API | L40S or datacenter 4090 provider |
Bottom line
Use 24 GB as the clean answer for FLUX.1 schnell. Treat 12 GB as the budget answer if you are comfortable with quantization and occasional workflow tuning.
Source note: Black Forest Labs' model card describes FLUX.1 schnell as a 12B parameter rectified flow transformer. The VRAM guidance above is practical deployment guidance, not an official minimum.
Related reading: Best GPU for FLUX Image Generation.