Jamba 1.5 Mini
52B-A12BAI21 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⚠ Superseded · Prefer Ministral 3 8B Instruct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.
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
Similar models
Compare with Llama 3.1Llama 3.1 70B Instruct
Meta Llama 3.1
Meta's frontier 70B model. Requires 40GB+ VRAM; dual 3090 or M2 Ultra.
Llama 3.3 70B Instruct
Meta Llama 3.3
Latest Meta 70B with improved multilingual. Drop-in upgrade from Llama 3.1 70B.
GPT-OSS 120B
OpenAI GPT-OSS
The big GPT-OSS (117B total / 5.1B active). Native MXFP4 checkpoint is ~61GB — fits one 80GB card or a 128GB unified-memory Mac. Partial offload on 24GB consumer cards is slow but works.
GLM-4.5-Air
Zhipu GLM-4.5
Zhipu's agentic/reasoning MoE (106B total / 12B active). Q4 ~64GB — the sweet spot is a 96GB+ unified Mac or 2× 48GB cards. Strong tool-calling for its class.
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.
- Runs comfortably on
- A100 40G40GB · +7.0A40 48G48GB · +15.0L40S 48G48GB · +15.0Radeon PRO W7900 48G48GB · +15.0DGX Spark 64G64GB · +31.0
- Tight but possible
- RTX 509032GBArc Pro B70 32G32GBRadeon AI PRO R9700 32G32GB
- Compared here
- GGUF vs AWQ
- Try it yourself
- Size it in the calculatorGenerate the run command
How to actually run this
Deployment guides for this model and this class of hardware.
This page's figures change when the model or the runtime does.Last updated 2026-10-20 RSS → /feed.xml