Can RTX 5090 run Qwen3.8 Flash-Next?

Partly: part of the model runs from system RAM (CPU offload, per the source). Measured 159.2 tok/s generation with part of the model offloaded to system RAM (Strata, IQ3_S (~55 GB), experts offloaded to RAM, speculation helper; source).

Every measured result for Qwen3.8 Flash-Next on RTX 5090

Build	Quant / setup	Engine	tok/s
RTX 5090 workstation: Qwen3.8 Flash-Next IQ3_S at 159.2 tok/s on Strata (expert offload)	IQ3_S (~55 GB), experts offloaded to RAM, speculation helper	Strata	159.2 CPU offload	source
Ryzen 9 9950X3D + RTX 5090 + 128 GB DDR5: four big MoEs with experts offloaded to RAM (Qwen3.8 Flash-Next 78.8 tok/s)	Unsloth UD-Q5_K_XL, MTP drafting, experts offloaded to RAM	Strata (296b59d)	78.8 CPU offload	source

Memory: RTX 5090 has 32 GB. Qwen3.8 Flash-Next weights are about 110.1 GB at Q4_K_M (180B params × 4.89 bits ÷ 8, before context/KV cache). Arithmetic, not a measurement; long contexts need more. Check other quants in the VRAM calculator.

Speeds are decode (generation) tokens/sec as reported by each source; quant, engine and context differ, so small gaps are noise.

All measured speeds for Qwen3.8 Flash-Next: best home rig for Qwen3.8 Flash-Next.

Qwen3.8 Flash-Next on other hardware: 2x Intel Arc Pro B70 · 2x RTX 5070 Ti · 2x RTX 5080 · 2x RTX PRO 4000 Blackwell · 2x Tesla V100 32GB · DGX Spark (GB10)

Other models measured on RTX 5090: DeepSeek V4.1 Flash · GLM-5.3 Flash · Gemma 4 12B · Gemma 4 26B-A4B · Gemma 4 31B · Ornith 1.5 122B · Qwen3.5 9B · Qwen3.6 27B · Qwen3.6 35B-A3B · Qwen3.8 27B · gpt-oss 20B

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