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How much VRAM does Llama 4 Scout (17B active / 109B total) need at Q4_K_M? Native 10M Context

Full context is a multi-terabyte estimate even with expert offload. Reduce context before planning a small deployment, and verify engine support, offload behavior, and actual memory use.

At Q4_K_M and 10,485,760 tokens, this model estimates 2335 GB with all 109B parameters resident. The configured architecture has 48 layers, 8 KV heads, and head dimension 128. Each token only uses 17B parameters, but that doesn't shrink what has to stay loaded, because different tokens pick different experts. These are planning estimates, not guarantees for a particular inference engine.

By TechCompare · Updated

Total VRAM required
2335 GB
Llama 4 Scout (MoE 17B/109B) at Q4_K_M
Weights
61.0 GB
109B params
KV cache
2062 GB
10240K tokens, FP16 KV

Calculator

Estimated VRAM required

2335 GB

109B params at Q4_K_M, 10,485,760 token context, batch 1, inference.

Weights
61.0 GB
KV cache
2062 GB
Overhead
212 GB

Estimate accuracy: Weights within ~2%. KV cache within ~5% for standard GQA models, ~10% for MLA or hybrid state estimates. Real VRAM may vary with framework (vLLM vs llama.cpp vs Transformers), Flash Attention, and driver overhead.

KV cache exceeds model weights: Consider lowering the context length to save on VRAM. Contexts between 8K and 64K are generally more typical for local setups.

Hardware that fits

Apple entries show installed unified memory separately from a model budget based on an 8 GB reserve. That budget is a planning heuristic, not a fixed hardware limit.

No single GPU in our catalog has enough memory. Multi-GPU or CPU offload required.

How this is calculated

Weights are 109B x 0.56 bytes = 61.04 GB. FP16 KV cache is 8 heads x 128 head dimension x 48 layers x 10,485,760 tokens x 2 (K and V) x 2 bytes = 2061.58 GB. The calculator adds 10% of weights plus cache as overhead: 212.26 GB, for 2334.89 GB total.

Verdict

Each token needs 196,608 bytes of FP16 KV storage under this model, or 196.6 GB per million tokens. The configured 10,485,760 tokens require 2061.58 GB of cache. Adding weights and 10% overhead gives 2334.89 GB resident. Dividing resident memory by nominal capacity gives at least 30 80-GB GPUs or 17 141-GB GPUs, before distribution constraints and additional runtime needs. At 32,768 tokens, the resident estimate drops to about 74 GB.

More Llama scenarios

MiMo-V2.6-Pro at Q4_K_M
Budget a 1.02T expert pool, hybrid attention, and a 1M text context.
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MiMo-V2.6-Flash at Q4_K_M
309B total weights and separate global and sliding cache widths.
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GLM-5.3-Flash at Q4_K_M
Model the 34 KDA layers, 11 sparse layers, and indexer storage.
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Frequently asked questions

What's iRoPE and why does it support 10M context?
Scout uses interleaved attention and positional encoding to support its advertised long context. This calculator uses a full KV allocation across the configured 48 layers. Actual engine implementations may use different cache strategies. Maverick has a separate 1M-token context specification.
Can Scout run on a single 24 GB GPU?
Not at the configured 10M context: the modeled cache alone is about 2062 GB. Even at 32,768 tokens, the resident estimate is about 74 GB. Moving expert weights to system RAM cuts VRAM, but the host then has to hold them and every token gets slower, so measure real memory use before counting on a 24 GB card.
What about Maverick (17B/400B)?
Same active params (17B), 4x larger expert pool. Resident is ~250 GB at Q4 (multi-GPU). Stronger reasoning than Scout but the native context window is 1M.