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How much VRAM does MPT 30B Instruct need?

By Bitpute · Published 12 July 2026 · Updated 24 July 2026 · How we estimate · Sources · Editorial policy · Version history · Report an error · Figures re-checked against the calculation engine on every build

MPT 30B Instruct needs about 18.5 GB of VRAM at Q4_K_M, or 31.9 GB at Q8_0 and 59.4 GB at FP16. That fits a consumer card: the smallest in our set that holds it at Q4_K_M is the RTX 3090 (24 GB). Weights plus runtime overhead; with only 8K of context the cache stays small.

Weights-plus-runtime footprint across the six most common quantizations. KV cache is context-dependent and comes on top. A full 8K window is a real share of the budget; size it precisely in the GPU Memory Calculator.

This is the instruction-tuned checkpoint: the same architecture and the same memory footprint as the base model, fine-tuned to follow prompts and hold a conversation. If you intend to fine-tune on your own data, start from MPT 30B instead.

Parameters30B
Context8K
VendorMosaicML
LicenseApache-2.0
Released2023

Can your GPU run MPT 30B Instruct?

Pick your card — the answer below is computed by the same engine that produces every figure on this page.

Yes — recommended
Estimated VRAM18.5 GB
GPU VRAM24 GB
Headroom4.3 GB

RTX 3090 runs MPT 30B Instruct at Q4_K_M with 4.3 GB to spare; room left for context and everyday runtime pressure.

Weights plus runtime overhead. KV cache is not included — it depends on context length and this model’s published architecture.

Why
Weights (Q4_K_M)16.9 GB
Runtime overhead1.6 GB
Estimated total18.5 GB
Usable VRAM (95% of 24 GB)22.8 GB

Across every GPU we track

Estimates, not guarantees: real usage moves with runtime, driver, batch size and context. Size a specific context window in the GPU Memory Calculator.

How was this number calculated? Every figure here comes from Bitpute’s documented calculation methodology — parameters, precision, quantization, runtime overhead and usable VRAM, each formula written out in full.

Memory by quantization

QuantWeights+ runtime overhead
FP1655.9 GB59.4 GB
Q8_029.7 GB31.9 GB
Q6_K22.9 GB24.8 GB
Q5_K_M19.9 GB21.6 GB
Q4_K_M16.9 GB18.5 GB
Q4_015.7 GB17.3 GB

Overhead = 0.75 GB + 5% of weights (CUDA context, buffers). Add KV cache on top. A full 8K window is a real share of the budget.

Which quantization should you actually run?

MPT 30B Instruct is too large for a 12–16 GB card. On RTX 4090, Q4_K_M (18.5 GB) fits with room for everyday context lengths — the realistic single-GPU entry point. Higher quality (Q6_K 24.8 GB, FP16 59.4 GB) needs RTX A6000 or multiple GPUs — for occasional use, renting is usually cheaper than buying.

Single-GPU fit at Q4_K_M (18.5 GB + KV)

RTX 3060 12GBRTX 4060 Ti 16GBRTX 4070 Ti SUPERRTX 3090RTX 4090RTX 5090A100 40GBRTX A6000L40SA100 80GBH100 80GBH200 141GB

Size it exactly →Rent a GPU for it →

Where the memory goes

Memory budget for MPT 30B Instruct on a RTX 3090Stacked bar. Weights 16.9 GB, runtime overhead 1.6 GB, KV cache at 8K context 1.0 GB, against 22.8 GB usable on a RTX 3090.Memory budget for MPT 30B Instruct on a RTX 309022.8 GB usable of 24 GBWeights (Q4_K_M) — 16.9 GBRuntime overhead — 1.6 GBKV cache @ 8K — 1.0 GBHeadroom — 3.3 GB

Weights and overhead are exact for Q4_K_M. The KV bar assumes a generic 32-layer transformer at 8K context — your model’s layer count and attention scheme move it, which is what the calculator is for.

Weighing the cheapest card that fits against the next one up? RTX 3090 vs RTX 5090 compares them on bandwidth, power and which models each one holds.

Common questions

How much VRAM does MPT 30B Instruct need?

MPT 30B Instruct needs about 18.5 GB of VRAM at Q4_K_M, 31.9 GB at Q8_0, or 59.4 GB at FP16. That is weights plus about 0.75 GB of runtime overhead and 5% of weight size; KV cache is additional and depends on context length.

What GPU can run MPT 30B Instruct?

At Q4_K_M the smallest card in our set that fits is the RTX 3090 (24 GB usable at 95%). At FP16 you need the A100 80GB (80 GB) or larger.

Can MPT 30B Instruct run on 24 GB?

Yes. At Q4_K_M it needs about 18.5 GB, which fits inside the ~22.8 GB usable on a 24 GB card.

Same memory footprint as 1 other checkpoint

MPT 30B Instruct has an identical parameter count to this, so every figure on this page applies to it unchanged. What varies is different checkpoint roles (base) — not the size. Choose on capability and licence; the memory budget is identical.

MPT 30B

More in the MPT family

MPT 7BMPT 7B ChatMPT 7B InstructMPT 30B