RUN COMPATIBILITY

Can You Run FLUX.1 [dev] on NVIDIA RTX 4090?

VRAM breakdown, compatibility verdict, and live pricing for FLUX.1 [dev] (12B Rectified Flow Transformer) on NVIDIA RTX 4090.

✓

Compatible

Compatibility verdict for this model + hardware pair

VRAM Breakdown

Weight memory at different precision levels.

Precision	Model Weights	Fits on NVIDIA RTX 4090?
FP16 / BF16	23.8 GB	✓ Fits
INT8 / FP8	12.0 GB	✓ Fits
INT4 / AWQ	N/A (NF4: 7.0 GB)	✗ Exceeds VRAM

Max Context

1024×1024 image (FP8/NF4)

Inference Engine

ComfyUI + FP8/NF4 checkpoint

Est. Throughput

~5–8 sec/image (1024×1024)

VRAM Bandwidth

1,008 GB/s

Hardware Match Spec

GPU Capacity

24 GB GDDR6X

Memory bandwidth: 1,008 GB/s

Model Requirements

12.0 GB (INT8) + KV-Cache

Bandwidth required: ~1,008 sustained

Deployment Arithmetic for FLUX.1 [dev] on NVIDIA RTX 4090

The FLUX.1 [dev] (12B Rectified Flow Transformer) contains approximately 12 billion parameters. At FP16 (2 bytes per parameter), the raw weight matrix occupies 23.8 GB. With a 15% CUDA kernel overhead factor, effective VRAM for weights alone is 23.8 GB. The NVIDIA RTX 4090 provides 24 GB GDDR6X of memory, leaving a headroom of 1 GB for KV-cache and activation tensors.

At INT8 quantization (1 byte per parameter), the weight footprint drops to 12.0 GB, requiring a tensor parallel degree of approximately 1× across NVIDIA RTX 4090 instances. The estimated inference throughput is ~5–8 sec/image (1024×1024), which translates to a cost-per-million-output-tokens of roughly $2.00 at current spot rates. For production deployments, ComfyUI + FP8/NF4 checkpoint with PagedAttention is the recommended serving stack.

Live Pricing — NVIDIA RTX 4090

Spot and on-demand rates for RTX 4090-class hardware.

Provider	GPU	VRAM	Spot	On-Demand
Vast.ai	RTX 4090	24GB GDDR6X	$0.34/hr	$0.85/hr
Spheron	RTX 4090	24GB GDDR6X	$0.69/hr	$1.73/hr
RunPod	RTX 4090	24GB GDDR6X	$0.74/hr	$1.85/hr
Lambda Labs	RTX 4090	24GB GDDR6X	$0.89/hr	$2.23/hr

View All 40+ Cloud GPUs on Full Pricing Index →

Frequently Asked Questions

Can FLUX.1 [dev] run on NVIDIA RTX 4090?▾

Yes. FLUX.1 [dev] is compatible with NVIDIA RTX 4090 (24 GB GDDR6X). At the recommended precision, the model requires 12.0 GB (INT8) or N/A (NF4: 7.0 GB) (INT4), fitting within available VRAM with headroom for KV-cache.

What is the maximum context length?▾

The maximum supported context length is 1024×1024 image (FP8/NF4). Longer contexts require more VRAM for KV-cache and may cause CUDA OOM errors.

What inference engine should I use?▾

Recommended: ComfyUI + FP8/NF4 checkpoint. This configuration is optimized for the hardware's memory bandwidth and compute capabilities.