How much VRAM does FLUX.1 [schnell] need?
FLUX.1 [schnell] needs about 38 GB of GPU memory at FP16 and about 13.6 GB at 4-bit. Pick a precision below to see which ComputeBD AI Computer fits and what it costs per hour in taka.
You need about 38 GB of GPU memory to run FLUX.1 [schnell] at FP16 / BF16.
- Model weights 31.5 GB
- Runtime & working space 6.5 GB
NVIDIA L40S is the most affordable AI Computer that fits — ৳343/hour, billed by the minute.
| AI Computer | Fits? | Speed (1 user) | Price |
|---|---|---|---|
| NVIDIA L424 GB | Too small |
— | ৳147/hr |
| NVIDIA A1024 GB | Too small |
— | ৳196/hr |
| NVIDIA L40S48 GB | Fits |
— | ৳343/hr |
| NVIDIA A10080 GB | Fits |
— | ৳638/hr |
| NVIDIA H10080 GB | Fits |
— | ৳1,047/hr |
| NVIDIA H200141 GB | Fits |
— | ৳1,390/hr |
| NVIDIA B200180 GB | Fits |
— | ৳1,652/hr |
| NVIDIA B300288 GB | Fits |
— | ৳1,880/hr |
FLUX.1 [schnell] at each precision
| Precision | GPU memory needed | Cheapest ComputeBD AI Computer |
|---|---|---|
| FP32full precision — rarely needed | 72 GB | NVIDIA A100 · ৳638/hr |
| FP16 / BF16standard — original quality | 38 GB | NVIDIA L40S · ৳343/hr |
| 8-bitalmost no quality loss | 22.1 GB | NVIDIA L4 · ৳147/hr |
| 4-bit (GGUF / AWQ / GPTQ)small quality loss, ~4× less memory | 13.6 GB | NVIDIA L4 · ৳147/hr |
- Made by
- Black Forest Labs
- Parameters
- 16.9B
- Hugging Face
- black-forest-labs/FLUX.1-schnell
How the estimate works
- Weights = parameters × bytes per parameter (FP16 = 2 bytes, 8-bit ≈ 1, 4-bit ≈ 0.56).
- KV cache (conversation memory) grows with context length and the number of people at once: 2 × layers × KV-heads × head size × tokens × 2 bytes.
- Runtime: about 1 GB for CUDA plus ~8 % of the weights for working space.
- Fine-tuning: LoRA keeps an FP16 copy of the model and trains ~1 % extra parameters; QLoRA keeps a 4-bit copy; full fine-tuning needs ~16 bytes per parameter. Gradient checkpointing is assumed.
- Speed: generating text for one user is limited by memory bandwidth, so tokens/second ≈ bandwidth × 60 % ÷ model size.
These are good planning estimates, not guarantees: the real figure depends on the software (vLLM, llama.cpp, Transformers…), settings and your data. Leave ~10 % spare.
VRAM needed, model by model
Frequently asked questions
How much VRAM does FLUX.1 [schnell] need?
About 38 GB at FP16 (original quality) and about 13.6 GB at 4-bit, for one user with a 4k context.
Which GPU can run FLUX.1 [schnell]?
At full quality it fits on an NVIDIA L40S (48 GB), ৳343/hour on ComputeBD.
Try it on a real AI Computer
JupyterLab opens in about a minute. Pay in taka with bKash, billed by the minute — stop whenever you like.