Can ai21labs AI21 Jamba Reasoning 3B run on RTX 4000 Ada 20GB?

YES — Runs Great

C45Usable

Estimated from fit model

ai21labs AI21 Jamba Reasoning 3B needs ~5.4 GB VRAM. RTX 4000 Ada 20GB has 20.0 GB. With Q4_K_M quantization, expect ~42 tok/s.

Runtime: OllamaCapacity: RoomyBandwidth: LowStack: BasicBottleneck: Balanced

Operating mode

Choose the run profile you care about

Interactive favors responsiveness, while light API and scale-out lean harder on serving readiness. The fit stays the same, but the recommendation lens changes.

Current mode

Balanced

Balanced for general local use. Keeps the ranking neutral across personal and serving workflows.

Capabilities:

Select quantization to explore

Q4_K_M (Medium quality) — 5.4 GB, 42.0 tok/s, Runs well

5.4 GB required20.0 GB available

27% VRAM used

Fit status

Runs well

Decode

42.0 tok/s

TTFT

4610 ms

Safe context

681K

Memory

5.4 GB / 20.0 GB

Memory breakdown

Weights1.8 GB

KV Cache0.4 GB

Runtime1.2 GB

Headroom2.0 GB

See how fast it feels

See how fast it feelsai21labs AI21 Jamba Reasoning 3B on RTX 4000 Ada 20GB
1st promptCold start — includes initialization
>Solve: If a train travels at 60 mph for 2.5 hours, how far does it go?
Let me work through this step by step.

Given information:
  - Speed = 60 mph (miles per hour)
  - Time  = 2.5 hours

Formula: Distance = Speed x Time

Calculation:
  Distance = 60 mph x 2.5 h
           = 150 miles

The train travels 150 miles.

Double-check: at 60 mph the train covers 60 miles each hour. In half an hour it covers 30 miles. So in 2.5 hours: 60 + 60 + 30 = 150 miles. Confirmed.
2nd promptWarm — model ready, no init overhead
>What if the train stops for 20 minutes halfway?
The stop doesn't change the total distance covered while moving, but it affects total trip time.

Breakdown:
  - First half: 1.25 hours at 60 mph = 75 miles
  - Stop: 20 minutes (no distance)
  - Second half: 1.25 hours at 60 mph = 75 miles

Total distance: 150 miles (same)
Total time: 2.5 h + 0.33 h = 2.83 hours
Average speed: 150 / 2.83 = 53 mph

The distance stays the same but average speed drops to 53 mph because of the stop.
Estimated: 42.0 tok/s decode · 4.6s TTFT (warm) · 105 tok/s prefill

What limits this setup

This setup is broadly balanced for this model.

No major red flags

This recommendation has enough memory headroom and acceptable estimated speed for the selected workload.

Best improvement path

Performance by workload

Workload	Grade	Fit	Decode	TTFT	Context
Chat	C	Runs well	42.0 tok/s	2514 ms	681K
Coding	C	Runs well	42.0 tok/s	4610 ms	681K
Agentic Coding	C	Runs well	42.0 tok/s	6705 ms	681K
Reasoning	C	Runs well	42.0 tok/s	5448 ms	681K
RAG	C	Runs well	42.0 tok/s	8381 ms	681K

Quantization options

How ai21labs AI21 Jamba Reasoning 3B (3B params) fits at each quantization level on RTX 4000 Ada 20GB (20.0 GB usable).

Quant	Bits	VRAM	Quality	Fit
Q2_K	2	1.2 GB	Low	C44
Q3_K_S	3	1.5 GB	Low	C44
NVFP4	4

Get started

Copy-paste commands to run ai21labs AI21 Jamba Reasoning 3B on your machine.

Run

lms load hf-bartowski--ai21labs-ai21-jamba-reasoning-3b-gguf && lms server start

Upgrade options

Hardware that runs ai21labs AI21 Jamba Reasoning 3B well

MacBook Pro M4 32GBBudget pick

32 GB Unified (+12)

This setup is broadly balanced for this model.42 tok/s decode

~$799 MSRP

Mac mini M4 32GBBest value

32 GB Unified (+12)

This setup is broadly balanced for this model.42 tok/s decode

~$1,099 MSRP

Frequently asked questions

Can RTX 4000 Ada 20GB run ai21labs AI21 Jamba Reasoning 3B?

Yes, RTX 4000 Ada 20GB can run ai21labs AI21 Jamba Reasoning 3B with a C grade (Runs well). Expected decode speed: 42.0 tok/s.

How much VRAM does ai21labs AI21 Jamba Reasoning 3B need?

ai21labs AI21 Jamba Reasoning 3B (3B parameters) requires approximately 5.4 GB of memory with Q4_K_M quantization.

What is the best quantization for ai21labs AI21 Jamba Reasoning 3B?

The recommended quantization for ai21labs AI21 Jamba Reasoning 3B is Q4_K_M, which balances quality and memory efficiency.

What speed will ai21labs AI21 Jamba Reasoning 3B run at on RTX 4000 Ada 20GB?

On RTX 4000 Ada 20GB, ai21labs AI21 Jamba Reasoning 3B achieves approximately 42.0 tokens per second decode speed with a time-to-first-token of 4610ms using Q4_K_M quantization.

Can RTX 4000 Ada 20GB run ai21labs AI21 Jamba Reasoning 3B for coding?

For coding workloads, ai21labs AI21 Jamba Reasoning 3B on RTX 4000 Ada 20GB receives a C grade with 42.0 tok/s and 681K context.

What context window can ai21labs AI21 Jamba Reasoning 3B use on RTX 4000 Ada 20GB?

On RTX 4000 Ada 20GB, ai21labs AI21 Jamba Reasoning 3B can safely use up to 681K tokens of context. The model's official context limit is —, but available memory constrains the safe maximum.

See all results for RTX 4000 Ada 20GB See all hardware for ai21labs AI21 Jamba Reasoning 3B

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