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Run LLM Locally

Mixtral 8x7B Instruct on the RTX 5090

With 32 GB of VRAM, the RTX 5090 runs Mixtral 8x7B Instruct at Q4_K_M entirely on the GPU with an 8K context (about 27.5 GB needed). At Q8_0 it does not fit in VRAM.

Mixtral 8x7B Instruct

Q4_K_M · 8K context

Compatible

The model needs about 27.5 GB and fits in the 31 GB available (3.5 GB left).

Your hardware
RTX 5090 32 GB · 64 GB RAM
Estimated memory
~27.5 GB estimate
VRAM (usable memory)
31 GB
GPU only
Yes
CPU/GPU offload
Not required
Generation speed
103–154 tok/s estimate
Largest context in fast memory
32K tokens
Confidence: low

Based on: memory bandwidth (1,792 GB/s) and model size

Memory breakdown

~27.5 GB (26.8 GB–28.3 GB) needed · estimate

Fits entirely in VRAM · 3.5 GB left

  • Model weights24.6 GB
  • KV cache1 GB
  • Runtime overhead0.6 GB
  • Safety margin1.3 GB
Assumptions: context 8K tokens · KV cache f16 · llama.cpp (CUDA) · flash attention on · weights = real file size

EstimateData updated 24 days agoSource: Run LLM Locally engine, Hugging Face config.json + model card

What makes this estimate less reliable

  • no benchmark for this hardware and model yet
  • mixture-of-experts: speed depends on expert routing

Other quantizations on the RTX 5090

Mixtral 8x7B Instruct on RTX 5090 + 64 GB RAM · 8K context
Mixtral 8x7B Instruct Q8_08K~50.2 GB · 3.5–6.5 tok/s estimateCPU/GPU offload
Mixtral 8x7B Instruct Q6_K8K~39.2 GB · 7.5–15 tok/s estimateCPU/GPU offload
Mixtral 8x7B Instruct Q5_K_M8K~33.2 GB · 23–44 tok/s estimateCPU/GPU offload
Mixtral 8x7B Instruct Q4_K_M8K~27.5 GB · 103–154 tok/s estimateCompatible
Mixtral 8x7B Instruct IQ4_XS8K~27.1 GB · 104–156 tok/s estimateCompatible
Mixtral 8x7B Instruct Q3_K_M8K~21.6 GB · 122–186 tok/s estimateExcellent

Alternatives

Where to buy a RTX 5090

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GeForce RTX 5090

32 GB GDDR7 · 1,792 GB/s · 575 W

CompatibleRuns Mixtral 8x7B Instruct Q4_K_M entirely in memory

Price not available

Availability unknown

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Frequently asked questions

Can the RTX 5090 run Mixtral 8x7B Instruct?
The model needs about 27.5 GB and fits in the 31 GB available (3.5 GB left).
Which quantization should I use on the RTX 5090?
Q4_K_M is the highest-precision quantization that fits entirely in VRAM at 8K context. ~27.5 GB / 31 GB.
What is the largest context on the RTX 5090?
At Q4_K_M, about 32K tokens fit entirely in VRAM with an f16 KV cache. A q8_0 KV cache roughly doubles that.
How fast is Mixtral 8x7B Instruct (RTX 5090)?
We estimate 103–154 tok/s (estimate, confidence low). Based on: memory bandwidth (1,792 GB/s) and model size.