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Mistral AIMoE

Mistral Small 4 (119B MoE) RAM Calculator

Mistral AI's premier production-grade MoE model. Unifies instruction following, image/text inputs, and multi-step agentic workflows with low memory footprint.

Standard Recommendation

96GB RAM

Calculated for 4-bit (Q4_K_M) @ 8K Context

1. Select Quantization Level

Quantization compresses model weights to reduce RAM usage, with minor impacts on output quality.

2. Set Target Context Length

Longer contexts require more active memory for the Key-Value (KV) cache.

8,192 tokens
1K tokens32K64K128K tokens

Inference Bandwidth & Speed Matrix

Estimates generation speeds (tokens per second) based on physical memory channel bandwidth constraints.

DDR4 CPU Mode

45 GB/s

0.7 t/s

DDR5 CPU Mode

96 GB/s

1.4 t/s

Mac Unified Memory

300 GB/s

4.5 t/s

GPU VRAM (RTX 4090)

1008 GB/s

15.1 t/s

*Token throughput calculated strictly from weight volume transfers over memory channels. Actual generation speeds can be further throttled by processing threads or VRAM offloading parameters.

Technical Specifications

Total Parameter Count119 Billion
Active Parameters Per Token6.5 Billion
Maximum Context Window256K tokens
Primary Framework SupportOllama, llama.cpp, ExLlamaV2, vLLM

GPU & VRAM Sizing Profile

Multi-GPU Workstation / Mac Studio
Est. VRAM Required72.9 GB VRAM
Target GPU Hardware4x RTX 3090 / 4090 (96GB VRAM) or Apple Mac Studio (128GB Unified Memory)

Hardware Profile: Advanced workspace setup. Apple Silicon Mac Studios with Unified Memory provide a massive cost-saving advantage here by utilizing pooled high-bandwidth shared RAM.

Mistral Small 4 (119B MoE) Memory FAQs

How much RAM does Mistral Small 4 (119B MoE) require?

To run Mistral Small 4 (119B MoE) locally, memory size depends on your selected quantization. At 4-bit compression (Q4_K_M), the weights take up ~66.9GB of RAM. When combined with context cache and OS overhead, a standard **96GB system memory kit** is recommended. Unquantized FP16 execution requires a **256GB memory setup**.

What are the hardware requirements to run Mistral Small 4 (119B MoE) at FP16 precision?

Running Mistral Small 4 (119B MoE) at unquantized 16-bit precision requires loading ~238GB of model weights directly into VRAM or system memory. A minimum system memory target of **256GB RAM** is required to run the weights stably and avoid out-of-memory crashes.

Is Mistral Small 4 (119B MoE) dense or Mixture-of-Experts (MoE)?

Mistral Small 4 (119B MoE) is built on a **MoE** architecture. It has a total of 119 Billion parameters, but only activates 6.5 Billion parameters per token. While active parameter sparse execution makes token computing very fast, the entire 119B parameters must reside in VRAM/RAM for fast expert switching during execution.

How does context window size affect RAM usage for Mistral Small 4 (119B MoE)?

Context size directly scales the size of the Key-Value (KV) cache. At a standard 8,192 token context, the KV cache for Mistral Small 4 (119B MoE) uses ~0.02GB. If you scale this to 256K tokens, the KV cache can scale past hundreds of GBs, requiring multi-GPU or workstation-class RAM configurations.