Can RTX 4070 12GB run Step-3.5-Flash?

NVIDIA · 12 GB GDDR6X · 504 GB/s bandwidth · StepFun · 196.8B (active 11.0B) · MoE · model ctx up to 256K

No — Step-3.5-Flash at Q4 needs ≈ 110.34 GB even at 4K context, beyond the RTX 4070 12GB's 12 GB GDDR6X. It would only run with heavy CPU/disk offload. FP16 needs ≈ 396.8 GB — does not fit on this card. Estimates come from memory-bandwidth math; rows tagged measured override estimates. Relative ranking is more reliable than absolute tok/s. Methodology.

Fit & speed by quant and context

Quant	Context	VRAM needed	Fits?	tok/s (decode)
Q4	4K	110.34 GB	No	—
Q4	8K default	111.44 GB	No	—
Q4	32K	118.04 GB	No	—
FP16	4K	395.7 GB	No	—
FP16	8K default	396.8 GB	No	—
FP16	32K	403.4 GB	No	—

Fits = weights + KV(ctx) + 1 GB overhead ≤ 95% of VRAM. Measured anchors are context-agnostic; the fit verdict is recomputed per context. A missing tok/s means the model is far beyond this card (offload-only territory).

VRAM breakdown at 8K context

Quant	Weights	KV cache	Overhead	Total needed	RTX 4070 12GB VRAM
Q4	108.24 GB	2.2 GB	1 GB	111.44 GB	12 GB
FP16	393.6 GB	2.2 GB	1 GB	396.8 GB	12 GB

Other GPUs that run Step-3.5-Flash

• B200 192GB SXM — ≈462.8 tok/s Q4 est.
• MI300X 192GB — ≈306.6 tok/s Q4 est.
• H200 141GB SXM5 — ≈277.7 tok/s Q4 est.
• Gaudi 3 128GB — ≈189.5 tok/s Q4 est.
• Mac Studio M2 Ultra 192GB — ≈46.3 tok/s Q4 est.
• MacBook Pro M4 Max 128GB — ≈31.6 tok/s Q4 est.
• MacBook Pro M3 Max 128GB — ≈23.1 tok/s Q4 est.

All GPUs for Step-3.5-Flash →

Other models for the RTX 4070 12GB

• MiniCPM5-1B — ≈297.0 tok/s Q4 est.
• Llama-3.2-3B-Instruct — ≈160.7 tok/s Q4 measured
• Qwen3.5-2B — ≈160.4 tok/s Q4 est.
• Qwen3-4B-Instruct-2507 — ≈80.2 tok/s Q4 est.
• Qwen3-4B-Thinking-2507 — ≈80.2 tok/s Q4 est.
• NVIDIA-Nemotron-3-Nano-4B-BF16 — ≈80.2 tok/s Q4 est.
• gemma-4-E2B-it — ≈62.9 tok/s Q4 est.
• Llama-3.1-8B-Instruct — ≈52.1 tok/s Q4 measured

All models on the RTX 4070 12GB →