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Computed

Mixtral 8x7B Instruct on an H200 141GB (SXM)

Yes — the unquantized weights fit with room for 32k tokens of context.

Verdict

Fits at FP16

129.7 GiB usable of 141 GB

Weights (Q4_K_M)

26.3 GiB

87.0 GiB at FP16 · 46.7B params · 1 of 6 quant rows are measured files

KV cache

128.0 KiB per token at FP16

32 layers × 8 KV heads × 128 dimensions

Speed ceiling

179 tok/s

4800 GB/s ÷ bytes read per token

Every quant, against this card

Weight bytes are the size of the real published file wherever one exists — 1 of these6 rows are measured from the published checkpoint, the rest computed from the parameter count. Max context is what the KV cache can grow to in whatever memory the weights leave behind, capped at the 32k tokens this model was trained to address.

129.7 GiB usableFP16 / BF16 · 87.0 GiBQ8_0 · 46.2 GiBQ6_K · 35.7 GiBQ5_K_M · 30.8 GiBQ4_K_M · 26.3 GiBQ3_K_M · 21.3 GiB
Bars are the weight bytes at each precision; the dashed line is the usable memory of an H200 141GB (SXM). Drawn from the computed byte counts, not sketched.
PrecisionBits/weightWeightsSourceFitsMax contextCeiling
FP16 / BF1616.0087.0 GiBmeasured fileyes32,768 (model cap)179 tok/s
Q8_08.5046.2 GiBnominalyes32,768 (model cap)325 tok/s
Q6_K6.5635.7 GiBnominalyes32,768 (model cap)413 tok/s
Q5_K_M5.6730.8 GiBnominalyes32,768 (model cap)470 tok/s
Q4_K_M4.8326.3 GiBnominalyes32,768 (model cap)542 tok/s
Q3_K_M3.9121.3 GiBnominalyes32,768 (model cap)651 tok/s

What the context actually costs

The KV cache is 2 · layers · kv_heads · head_dim bytes per token per element — 2 · 32 · 8 · 128 · 2 B = 128.0 KiB. It depends on the key/value head count, not the attention-head count and not the parameter count. This model shares 8 KV heads across 32 query heads, which divides the cache by 4 against multi-head attention.

ContextKV cache (FP16)KV cache (8-bit)Plus Q4_K_M weights
4,096512 MiB256 MiB26.8 GiB
8,1921.0 GiB512 MiB27.3 GiB
32,7684.0 GiB2.0 GiB30.3 GiB

The speed ceiling, and where it comes from

Generating one token reads every active weight from memory once. At FP16 / BF16 that is 24.0 GiB — only 28% of the checkpoint, because this is a mixture of experts and each token is routed to 2 of 8, plus a pass over the KV cache. An H200 141GB (SXM) moves 4800 GB/s, so the arithmetic ceiling is 179 tok/s. Treat it as a bound, not an estimate: attention overhead, kernel launches and imperfect memory access keep real runtimes at roughly 60–80% of it, and nothing pushes past it.

Where these numbers come from

The model

Parameters
46,702,792,704
Layers
32
Attention / KV heads
32 / 8
Head dimension
128
Trained context
32,768
Checkpoint as published
87.0 GiB

Read from mistralai/Mixtral-8x7B-Instruct-v0.1. The parameter count is the Hub's own total over the tensor shapes, not a figure taken from the model's name.

The accelerator

Memory
141 GB HBM3e
Bandwidth
4800 GB/s
Assumed usable
92% → 129.7 GiB

Capacity and bandwidth from the vendor's specification. The usable fraction is an assumption, not a spec: a driver context, compute workspace and any attached display come out of the same pool before a weight is loaded.

Questions this pairing answers

How much VRAM does Mixtral 8x7B Instruct need?

87.0 GiB for the weights at FP16 — 46.7B parameters at two bytes each — and 26.3 GiB at Q4_K_M. The KV cache is on top of that and is not a fixed number: this model spends 128.0 KiB per token of context, so 8,192 tokens costs a further 1.0 GiB. An H200 141GB (SXM) makes 129.7 GiB of its 141 GB available on the assumption below.

Can an H200 141GB (SXM) run Mixtral 8x7B Instruct?

Yes — the unquantized weights fit with room for 32k tokens of context. That is the weights and the KV cache together, against 129.7 GiB of usable memory.

How fast will Mixtral 8x7B Instruct run on an H200 141GB (SXM)?

No faster than 179 tokens/second at FP16 / BF16, and in practice below it. Decoding is memory-bound: every token reads the 28% of weights this MoE routes to 24.0 GiB of weights plus the cache, and this card moves 4800 GB/s. That division is the ceiling — no kernel, runtime or driver beats it, and a real runtime typically reaches 60–80% of it.

Why does the context length change how much memory Mixtral 8x7B Instruct needs?

Because the KV cache holds one key and one value vector per token, per layer, for the whole conversation, and it is allocated separately from the weights. This model has 32 layers and 8 key/value heads of 128 dimensions, shared across 32 query heads — grouped-query attention, which divides the cache by 4. That works out at 128.0 KiB per token. Parameter count tells you nothing about this number.

The same model on a different card

A different model on the same card

All 62 models on H200 141GB (SXM) →

Method and limits. Weight bytes are the byte size of the real published file wherever one exists, and the model's exact parameter count times the published llama.cpp bits-per-weight where it does not. That distinction is on every row above and it matters at both ends: a sub-1B model's Q4_K_M file runs a third larger than the nominal figure because k-quants keep its embedding tables at higher precision, and an already-4-bit release cannot be quantized upward at all. The KV cache is 2 · layers · kv_heads · head_dim · bytes per token, summed over layers with each sliding-window layer capped at its window. The speed figure is a roofline bound, not a benchmark: bandwidth divided by bytes read per token, which no runtime exceeds and every runtime falls short of. The usable fraction of card memory is an assumption: 92% here, which is what this lane assumes for a dedicated card — the other class assumes 75%, so it is not one number applied to every device. That is the only assumed input on this page; every other figure is computed from the model config and the card's published specification. Nothing on this page is written by a language model. Architecture from the model's published config, fetched 2026-08-07.