Jamba 1.5 Mini

52B-A12B

AI21 Labs

⚠ Superseded · Prefer Ministral 3 8B Instruct

This index would suggest Ministral 3 8B Instruct instead today — more quant levels to choose from (2 → 3). The numbers below are still accurate; they are just for a model you probably should not start with. Compare the two →

AI21's hybrid Mamba-Transformer MoE: 52B total, about 12B active, 256K context. Only 4 of its 32 layers keep a KV cache, so long context is cheap — but all 52B of weights still have to be resident, about 31 GB at Q4. That is a 32 GB card or a large Mac, not the 16 GB card this entry used to claim. Sizes use the calculator's generic rates; no speed has been measured here.

Pro GPUMac / Apple Silicon

262K

Max Context

2

Quant Variants

GGUF Q4_K_M

Best Quality

96.6%

Accuracy Retained

Quantization Variants

Per-quant VRAM, quality loss, and inference speed on RTX 4090

Measured = run on this site · Estimated = not run here: calculated, or a figure this site has not verified · Community = public reports

FormatLevelBPWVRAMPPL LossSpeedSourceActions
GGUFQ4_K_M4.8531.5 GB3.4%—Estimated
CalcHF
AWQINT4426.0 GB4.8%—Estimated
CalcHF

Running Jamba 1.5 Mini locally

At Q4_K_M and 4K of context, Jamba 1.5 Mini needs about 33.0 GB — 29.9 GB of weights, 0.06 GB of KV cache and a 3.0 GB activation buffer. The smallest card in this index that clears that comfortably is the A100 40G at 40 GB, and 18 of the 78 cards here do. These are calculated figures, not measurements: the estimate stops counting a card as comfortable at 88% of its VRAM, which is roughly the room a desktop session needs.

What longer context costs

Going from 4K to 32K adds about 0.44 GB, taking the total to 33.5 GB. That is gentler than the parameter count suggests: only 4 of 32 layers keep a KV cache that grows with context, so the cache scales at a fraction of the usual rate. The model's native window is 256K; holding all of it at Q4_K_M would need about 37 GB.

Which build to download

This index tracks 2 formats for it — GGUF, AWQ — across 2 levels. Q4_K_M carries the lowest published perplexity loss at 3.4%. No throughput has been measured for this model on this site's hardware. GGUF runs on llama.cpp and Ollama across NVIDIA, AMD and Apple silicon; AWQ and GPTQ target vLLM on CUDA and ROCm; EXL2 is ExLlamaV2 — CUDA only, and now archived, so local use rather than serving.

Common questions

How much VRAM does Jamba 1.5 Mini need?
About 33.0 GB at Q4_K_M with 4K of context and batch 1, rising to roughly 33.5 GB at 32K. That figure is weights plus KV cache plus a 10% activation buffer, calculated from the model's architecture rather than measured on a card.
Will Jamba 1.5 Mini run on a 40GB GPU?
Yes — at Q4_K_M and 4K context it needs about 33.0 GB, which leaves 7.0 GB spare on a A100 40G. That is the smallest card in this index that clears it comfortably; 18 of 78 do.
Which quantization of Jamba 1.5 Mini should I use?
Q4_K_M has the lowest published quality loss (3.4%), and Q4_K_M is the level most people run. All 2 levels in the index are Q4_K_M, AWQ INT4. Note this is a mixture-of-experts model — all parameters must be resident even though only a fraction are active per token, so the memory cost follows the total, not the active count.

Where this model fits

Sized at Q4_K_M with a 4K context window, smallest card first. Comfortable means the estimate uses at most 88% of the memory.

Ships in
GGUFAWQ
Compared here
GGUF vs AWQ

This page's figures change when the model or the runtime does.Last updated 2026-10-20 RSS → /feed.xml