How to Deploy Qwen3.8 Flash Next Locally
Qwen3.8 Flash Next is a large MoE that Qwen released in August 2026. Officially it has 125B parameters, but it uses only 6B per token, so it generates nearly as fast as a small 7B-class model. The only hard part is fitting it: 4-bit is about 111 GB, so either a 128GB unified-memory machine holds it entirely, or you use one 16GB card plus 128GB of RAM and keep the experts in system RAM.
Qwen3.8 Flash Next details
- Min VRAM at 4-bit113 GB · 8K
- Parameters176B
- Active params6B
- Max context256K
- Architecture
- MoE
- Experts offloaded
- 5 GB VRAM + 110 GB RAM
- License
- Qwen Community License 1.0
- Launch date
- Aug 26, 2026
- Vendor
- Alibaba
- Hugging Face repo
- Qwen/Qwen3.8-Flash-Next
- GGUF repo
- unsloth/Qwen3.8-Flash-Next-GGUF
- NVFP4 repo (Blackwell)
- nvidia/Qwen3.8-Flash-Next-NVFP4
- MLX repo (Apple)
- mlx-community/Qwen3.8-Flash-Next-4bit
- Ollama tag
- qwen3.8-flash-next:125b-a6b-q4_K_M
- Layers
- 48
- Hidden size
- 2,560
- KV heads
- 2
- Head dim
- 256
How much VRAM does Qwen3.8 Flash Next need for local deployment?
| Quantization | WeightsGB | 8K contextGB | 32K contextGB | 128K contextGB | 256K context (max)GB |
|---|---|---|---|---|---|
| 1-bit | 74.5GGUF | 75.8 | 76.4 | 78.8 | 82 |
| 2-bit | 78.9GGUF | 80.2 | 80.8 | 83.2 | 86.4 |
| 3-bit | 90GGUF | 91.3 | 91.9 | 94.3 | 97.5 |
| 4-bit | 111.3GGUF | 112.6 | 113.2 | 115.6 | 118.8 |
| 5-bit | 158.3GGUF | 159.6 | 160.2 | 162.6 | 165.8 |
| 8-bit | 188.2GGUF | 189.5 | 190.1 | 192.5 | 195.7 |
| BF16/FP16 | 354GGUF | 355.3 | 355.9 | 358.3 | 361.5 |
Full calculation rules are on the Methodology page.
Can a single GPU run Qwen3.8 Flash Next?
No single graphics card holds the 4-bit version; the only standalone machines that fit it are 128GB unified-memory systems. 4-bit with 8K of context is about 113 GB, so even the largest single card, the RTX PRO 6000, has to drop to 2-bit or 3-bit, though it stays remarkably quick, at about 149 tokens/s for 2-bit. Machines like the DGX Spark and Ryzen AI Max+ 395 hold 4-bit at a little over 40 tokens/s. The model touches only about 6B parameters per token, so their modest bandwidth isn't much of a handicap. With one ordinary GPU, keep most of the experts in system RAM and leave only the parts every step needs on the card.
| Device | Price | Speed t/s | Max context |
|---|---|---|---|
| Ryzen AI Max+ 395 128GBWhole system · 128 GB | $4,46420 listings | 52.9 | 256K |
| Mac Studio M5 Ultra 96GBWhole system · 96 GB | $7,27412 listings | 130.5 | 256K |
| MacBook Pro M5 Max 128GBWhole system · 128 GB | $7,54920 listings | 94.1 | 256K |
| $8,24022 listings | 55.5 | 256K | |
| $18,99912 listings | 152 | 235K | |
| $22,50011 listings | 148.6 | 256K | |
| Mac Studio M3 Ultra 512GBWhole system · 512 GB | $22,90013 listings | 109.4 | 256K |
| Device | Price | Speed t/s | Max context |
|---|---|---|---|
| Ryzen AI Max+ 395 128GBWhole system · 128 GB | $4,46420 listings | 40.8 | 256K |
| MacBook Pro M5 Max 128GBWhole system · 128 GB | $7,54920 listings | 77.1 | 256K |
| $8,24022 listings | 42.9 | 256K | |
| Mac Studio M3 Ultra 512GBWhole system · 512 GB | $22,90013 listings | 91.7 | 256K |
| Device | Price | Speed t/s | Max context |
|---|---|---|---|
| Mac Studio M3 Ultra 512GBWhole system · 512 GB | $22,90013 listings | 66.3 | 256K |
Only common GPUs and systems are listed, one set for models under 50B and another for larger ones, sorted by price from low to high.
How many GPUs do you need to run Qwen3.8 Flash Next?
For 4-bit, the simplest setup is two 96GB RTX PRO 6000s, at about 129 tokens/s. On consumer cards, 2-bit is the practical choice: four 24GB RTX 3090s or RX 7900 XTXs hold it, at about 111 tokens/s. 4-bit plus 32K of context overflows four 24GB cards, and the next step up is eight. Four 32GB RTX 5090s are just enough for 4-bit and match the two RTX PRO 6000s on speed. 8-bit takes four RTX PRO 6000s. Qwen publishes deployment recipes for vLLM and SGLang.
| Device | Cards | Total price | Total VRAM | Speed t/s | Total power |
|---|---|---|---|---|---|
| 4 cards | $3,580 | 128 GB | 109.1 | 1,000 W | |
| Radeon RX 7900 XTX24 GB per card | 4 cards | $5,000 | 96 GB | 112.5 | 1,420 W |
| 4 cards | $7,196 | 96 GB | 111.1 | 1,400 W | |
| 4 cards | $7,400 | 128 GB | 88.4 | 920 W | |
| 2 cards | $9,798 | 96 GB | 100.6 | 600 W | |
| Instinct MI21064 GB per card | 2 cards | $9,988 | 128 GB | 139.8 | 600 W |
| 4 cards | $15,032 | 96 GB | 115.1 | 1,800 W | |
| 2 cards | $21,444 | 144 GB | 130 | 600 W | |
| 4 cards | $33,580 | 128 GB | 144 | 2,300 W | |
| 2 cards | $37,998 | 160 GB | 147.5 | 600 W | |
| 2 cards | No price | 96 GB | 115.1 | 900 W |
| Device | Cards | Total price | Total VRAM | Speed t/s | Total power |
|---|---|---|---|---|---|
| 4 cards | $3,580 | 128 GB | 92.8 | 1,000 W | |
| 4 cards | $7,400 | 128 GB | 73.1 | 920 W | |
| Instinct MI21064 GB per card | 2 cards | $9,988 | 128 GB | 124.5 | 600 W |
| Radeon RX 7900 XTX24 GB per card | 8 cards | $10,000 | 192 GB | 96.2 | 2,840 W |
| 8 cards | $14,392 | 192 GB | 94.9 | 2,800 W | |
| 4 cards | $19,596 | 192 GB | 84.6 | 1,200 W | |
| 2 cards | $21,444 | 144 GB | 114.1 | 600 W | |
| 8 cards | $30,064 | 192 GB | 98.8 | 3,600 W | |
| 4 cards | $33,580 | 128 GB | 129 | 2,300 W | |
| 2 cards | $37,998 | 160 GB | 132.9 | 600 W | |
| 2 cards | $45,000 | 192 GB | 129 | 1,200 W | |
| 4 cards | No price | 192 GB | 98.8 | 1,800 W |
| Device | Cards | Total price | Total VRAM | Speed t/s | Total power |
|---|---|---|---|---|---|
| 8 cards | $7,160 | 256 GB | 68.6 | 2,000 W | |
| 8 cards | $14,800 | 256 GB | 51.8 | 1,840 W | |
| 2 units | $16,480 | 256 GB | 26.9 | 480 W | |
| Instinct MI21064 GB per card | 4 cards | $19,976 | 256 GB | 98.8 | 1,200 W |
| 8 cards | $39,192 | 384 GB | 61.5 | 2,400 W | |
| 4 cards | $42,888 | 288 GB | 88.4 | 1,200 W | |
| 8 cards | $67,160 | 256 GB | 103.5 | 4,600 W | |
| 4 cards | $75,996 | 320 GB | 107.6 | 1,200 W | |
| 4 cards | $90,000 | 384 GB | 103.5 | 2,400 W | |
| 8 cards | No price | 384 GB | 74 | 3,600 W |
Full calculation rules are on the Methodology page.
What PC or server build do you need to run Qwen3.8 Flash Next locally?
When VRAM runs short, keep the experts in system RAM: the GPU holds only the shared parts every token uses plus a few experts, and the rest stays in RAM. Speed then depends mainly on memory bandwidth: at 4-bit, a dual-channel DDR4 desktop does about 17 tokens/s, a DDR5 desktop about 29, and a used 8-channel DDR4 server about 46. There's also Strata, an engine written specifically for this model, which runs the 2-bit version on a 12GB card with 64GB of RAM at more than twice the speed of llama.cpp.
2 × Tesla V100 32GB + Dual Xeon E5 DDR4
BudgetGeForce RTX 3090 + Single EPYC DDR4
Best valueGeForce RTX 5090 + Single EPYC DDR5
FlagshipGeForce RTX 5070 + Desktop DDR5
Home PCTesla V100 32GB + Dual Xeon E5 DDR4
BudgetGeForce RTX 3090 + Dual EPYC DDR4
Best valueGeForce RTX 5090 + Single EPYC DDR5
FlagshipTesla V100 32GB + Dual Xeon E5 DDR4
BudgetGeForce RTX 3090 + Dual EPYC DDR4
Best valueGeForce RTX 5090 + Single EPYC DDR5
FlagshipDetailed calculation rules are on the Methodology page.
As an eBay Partner, VRAMGlass may be compensated if you buy through the eBay links on this page. The price you pay stays the same.
What to know before running Qwen3.8 Flash Next locally
Why we list 176B parameters
The official 125B doesn't include the 51B n-gram lookup table or the 4B multi-token prediction layer. This site estimates VRAM from 125B plus the 51B lookup table, 176B in total, because the table takes up space too; but during generation it is only read as needed, so speed is still estimated from the 6B used per token.
Which quantization to pick
If RAM or VRAM is tight, pick 2-bit (about 79 GB) or 3-bit (about 90 GB), and move up to 4-bit (about 111 GB) if you have room; if answer quality matters, don't go below 3-bit. The quants Strata uses were made by ISTA-DASLab, who say their IQ3_S matches the original model on public benchmarks; this site hasn't re-tested that.
Which framework to use
For servers, Qwen recommends SGLang, KTransformers or vLLM. On a personal computer, llama.cpp and Ollama are the easiest; the Ollama tag is qwen3.8-flash-next:125b-a6b-q4_K_M. For speed on a 12GB to 24GB card, use Strata.
Official sampling parameters
Thinking mode:
temperature1.0,top_p0.95,top_k20. Non-thinking mode:temperature0.7,top_p0.8,top_k20,presence_penalty1.5.Long context takes almost no VRAM
Native context is 256K, extendable to 1M. Most of its layers use attention that doesn't grow with context, so the context cache is small: at 4-bit, going from 8K to 256K adds only about 6 GB of VRAM.
Launch commands
Ollama
- Windows
- macOS
- Linux
ollama run qwen3.8-flash-next:125b-a6b-q4_K_Mllama.cpp
- NVIDIA
- AMD
- Mac
- CPU
llama-server -hf unsloth/Qwen3.8-Flash-Next-GGUF:UD-Q4_K_XL -c 8192Short on VRAM? Add --cpu-moe to keep the routed experts in system RAM (about 110 GB needed).
llama-server -hf unsloth/Qwen3.8-Flash-Next-GGUF:UD-Q4_K_XL -c 8192 \ -ngl 99 --cpu-moe
vLLM
- Linux
- NVIDIA
- AMD
vllm serve Qwen/Qwen3.8-Flash-NextBlackwell GPUs (RTX 50 series, RTX PRO 6000, B200) run NVFP4 weights natively, at about 30% of the original size. For multiple GPUs, add --tensor-parallel-size with the card count.
vllm serve nvidia/Qwen3.8-Flash-Next-NVFP4MLX
- Apple Silicon
Vision models run on mlx-vlm: on a Mac, pip install mlx-vlm first; this command downloads the MLX weights from Hugging Face and starts a server.
mlx_vlm.server --model mlx-community/Qwen3.8-Flash-Next-4bitFile names follow that week's model-library snapshot; the definitions are in the methodology. Methodology
Other models in the Qwen family
| Model | Total params | Active params | 4-bit size |
|---|---|---|---|
| 8.2B | 8.2B | 5 GB | |
| 9.7B | 9.7B | 5.7 GB | |
| 27.8B | 27.8B | 16.8 GB | |
| 27.8B | 27.8B | 16.5 GB | |
| 32.8B | 32.8B | 19.8 GB | |
| 36B | 3B | 22.1 GB | |
| 2,446B | 95B | 1,310.9 GB |