Can the Radeon RX 7900 XTX run FLUX.1 dev?
FLUX.1 dev needs about 10 GB of VRAM at Q4/NF4 quantization for 1024×1024 image generation, so a 12 GB GPU such as the GeForce RTX 3060 12GB or RTX 4070 runs it. The FP16 checkpoint needs about 28.4 GB, which requires a 32 GB GPU, and FP8 checkpoints need about 17 GB.
At Q4_K_M quantization with 32,768 context, the FLUX.1 dev requires approximately 9.92GB of VRAM. The Radeon RX 7900 XTX has 24GB available (14.08GB headroom).
VRAM Breakdown
| Component | Size (GB) | Source |
|---|---|---|
| Model weights (Q4_K_M) | 7.2 | calculated |
| Loading overhead (10%) | 0.72 | calculated |
| Activation overhead | 2.0 | vendor_spec |
| Total required | 9.92 | |
| GPU memory available | 24 | vendor_spec |
| Headroom / shortfall | +14.08 |
Quantization Options
| Quant | Weights (GB) | Total @ 4K (GB) | Total @ 32K (GB) | Fits Radeon RX 7900 XTX? |
|---|---|---|---|---|
| Q4_K_M | 7.2 | 9.92 | 9.92 | Yes |
| Q5_K_M | 8.55 | 11.41 | 11.41 | Yes |
| Q6_K | 9.9 | 12.89 | 12.89 | Yes |
| Q8_0 | 12.75 | 16.03 | 16.03 | Yes |
| FP16 | 24 | 28.4 | 28.4 | No |
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Frequently Asked Questions
Can the FLUX.1 dev run on 24GB VRAM?
Yes. At Q4_K_M quantization with 4K context, the FLUX.1 dev needs approximately 9.92GB. Your 24GB of usable memory has 14.08GB headroom.
What is the maximum context length I can use on the Radeon RX 7900 XTX?
The FLUX.1 dev supports up to 32,768 tokens of context. Larger context increases KV-cache memory requirements. At 4K context the model needs ~9.92GB; at 32K it needs more.
Which quantization should I use with the Radeon RX 7900 XTX?
Q4_K_M is the recommended starting point — it offers the best speed-to-quality tradeoff. If you have VRAM headroom, Q6_K or Q8_0 improves quality at the cost of speed. FP16 is only for inference servers with ample memory.
Can an 8 GB GPU run FLUX.1 dev?
Not comfortably. Q4 weights plus activation overhead need about 10 GB of VRAM, so an 8 GB GPU must offload the text encoders to system RAM and use GGUF Q3/Q4 with reduced resolution, which degrades quality and adds minutes per image.
How much VRAM does FLUX.1 dev need at FP8?
FLUX.1 dev needs about 15 GB for FP8 weights alone and about 17 GB with activation overhead at 1024×1024, so a 16 GB GPU is the practical FP8 floor with encoder offload and a 24 GB GPU runs FP8 comfortably.
Related Pages
Full FLUX.1 dev fit page · All AI models · Radeon RX 7900 XTX specs · VRAM calculator
VRAM figures are calculated from model architecture parameters using established formulas. Benchmark data is measured and cited per row. GPU memory is vendor_spec from manufacturer datasheets.