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AI21 Jamba Large 1.5 — Hardware Requirements & GPU Compatibility

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AI21 Jamba Large 1.5 is a 398.6B-parameter open language model from AI21 Labs in the Jamba family. At BF16 it needs about 876.82 GB of VRAM — see which GPUs and Macs can run it below.

398.6B params · denseOther328 downloads220 likes

AI21 Jamba Large 1.5 runs on a multi-GPU server

BF16 needs ~884.5 GB · about 7× H200 SXM 141 GB

Other

Not set up for it?

Reference GPU · RTX 4090 24 GB

Estimates, ±20% · how we estimate

Run AI21 Jamba Large 1.5

One recommended way. Every other method, OS and quant is in the step-by-step guide.Each way opens a step-by-step guide for your OS and quant.

Recommended

vLLM on a multi-GPU server
tensor + pipeline parallel · needs vLLM on every node
$vllm serve ai21labs/AI21-Jamba-Large-1.5 --max-model-len 16384 --tensor-parallel-size 8

Size the nodes from the table above

Download: Weights on Hugging Face

install, other ways

Ways to runOther ways

each opens step-by-step

Run in cloud

Rent 7× H200 SXM · BF16

Estimated hourly price
~$25.13/hr
est., whole server
GPUs
7 GPUs
987 GB of VRAM

How Much VRAM Does AI21 Jamba Large 1.5 Need?

Select a quantization level; the listed hardware adheres to it.

QuantizationVRAM+32KRuns on
876.8 GB893.3 GB16-bit · bfloat — Brain floating point 16 — preferred for trainingRuns on 7× H200 SXM 141 GB
est.calculated, no published file yet

Selected BF16

Brain floating point 16

884.5GBat 16K context

Weights
875.4 GB
KV cache
8.8 GB
Overhead
0.3 GB

Server-class: ~884.5 GB at 16K context · about 7× H200 SXM 141 GB

Which Hardware Can Run AI21 Jamba Large 1.5?

BF16 · 876.8 GB

AI21 Jamba Large 1.5 (BF16) requires 876.8 GB of VRAM to load the model weights. For comfortable inference with headroom for KV cache and system overhead, 1140+ GB is recommended. No consumer GPU has enough memory.

Needs server-class hardware

AI21 Jamba Large 1.5 runs on a multi-GPU server · BF16 needs ~884.5 GB

Hardware that runs this model
HardwareQuantMemoryContextHardware page
7× H200 SXM 141 GB · 987 GBBF16884.5 GB16K ctxH200 SXM →BF16 · 884.5 GB · 16K ctx
6× B200 192 GB · 1.2 TBBF16884.5 GB32K ctxB200 →BF16 · 884.5 GB · 32K ctx

≤ 640 GB tier →

By VRAM tier · typical GPUs and Macs at BF16

Consumer GPUs (up to 32 GB) and Macs up to 512 GB: too small for this model (needs ≥ 884.5 GB)8 GB tier →12 GB tier →16 GB tier →24 GB tier →Macs →

How good is AI21 Jamba Large 1.5?

llmrun Score blends public benchmark boards into one number; 100 = the average open model.

Not enough data yet for an llmrun Score.

A Score needs results on enough independent boards. How the Composite Score is built

Benchmarks

Here are all 2 boards that have results for this model, sorted by their weight in the llmrun Score; badges show who ran the test.

  • LMArena Text

    LMArena · Oct 2026Arena

    1289.5

    #114/188 open

    Arena
  • MMLU-Pro

    TIGER-LabIndependent

    49.5%

    #76/146 open

    Independent

Alternatives to AI21 Jamba Large 1.5

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6
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Intern S2 397BInternLM—242.6 GBsame size
Ornith 1.5 397Bornith-ai—242.6 GBsame size
Trinity Large ThinkingArcee AI—799.6 GBsame size

Specifications

Publisher
AI21 Labs
Family
Jamba
Parameters
398.6B
Release Date
2024-08-19
License
Other

Frequently Asked Questions

How much VRAM does AI21 Jamba Large 1.5 need?

AI21 Jamba Large 1.5 requires 876.8 GB of VRAM at BF16.

VRAM = Weights + KV Cache + Overhead

Weights = 398.6B × 16 bits ÷ 8 = 797.1 GB

KV Cache + Overhead ≈ 79.7 GB (at 2K context + ~0.3 GB framework)

Fit ratings and hardware model lists check this model with room for a 16K-token context, which needs a little more memory.

VRAM usage by quantization

876.8 GB

Learn more about VRAM estimation →

Can NVIDIA GeForce RTX 5090 run AI21 Jamba Large 1.5?

No — AI21 Jamba Large 1.5 requires at least 876.8 GB at BF16, which exceeds the NVIDIA GeForce RTX 5090's 32 GB of VRAM.

Can I run AI21 Jamba Large 1.5 on a Mac?

AI21 Jamba Large 1.5 requires at least 876.8 GB at BF16. None of the 146 Macs we list has that much usable memory (the largest has 508.5 GB after macOS overhead).

Can I run AI21 Jamba Large 1.5 locally?

Yes — AI21 Jamba Large 1.5 can run locally on consumer hardware. Popular tools include Ollama, LM Studio, and llama.cpp.

What's the download size of AI21 Jamba Large 1.5?

At BF16, the download is about 797.11 GB.

Which GPUs can run AI21 Jamba Large 1.5?

No single consumer GPU has enough VRAM to run AI21 Jamba Large 1.5 at BF16 (876.8 GB). Multi-GPU or professional hardware is required.

Which devices can run AI21 Jamba Large 1.5?

AI21 Jamba Large 1.5 requires at least 876.8 GB at BF16, which exceeds the usable memory of every unified-memory device we list (the largest has 508.5 GB).