Jamba 1.5 Mini (non-reasoning)

A fast, affordable, open-weight model for simpler tasks.

Jamba 1.5 Mini (non-reasoning)

AI21 Labs' compact, open-weight model offering a massive 256k context window and high throughput at a very competitive price point.

Open Weight256k ContextAI21 LabsLow CostHigh SpeedMarch 2024 Data

Jamba 1.5 Mini is a compact, efficient, and open-weight language model developed by AI21 Labs. It represents a significant entry in the growing category of small, specialized models designed for speed and cost-effectiveness over raw reasoning power. Built on AI21's innovative Jamba architecture, which hybridizes traditional Transformer blocks with state-space model (SSM) components, it aims to deliver a unique balance of performance characteristics. This model is not intended to compete with flagship reasoning models like GPT-4 or Claude 3 Opus; instead, it carves out a niche for high-throughput, low-latency tasks where budget and responsiveness are paramount.

The standout feature of Jamba 1.5 Mini is its enormous 256,000-token context window, a size typically reserved for much larger, more expensive models. This capability, combined with its very low price point, creates compelling possibilities for applications that need to process or reference large volumes of text. Use cases like Retrieval-Augmented Generation (RAG) over extensive document sets, long-form conversation history management, and analysis of lengthy legal or financial reports become economically viable. The model's ability to 'see' and process this much information in a single pass is its primary value proposition.

However, this impressive context capacity comes with a significant trade-off: intelligence. On the Artificial Analysis Intelligence Index, Jamba 1.5 Mini scores a 4, placing it at the lower end of the spectrum (#29 out of 33 benchmarked models). This indicates that it is not well-suited for tasks requiring complex reasoning, multi-step problem-solving, or nuanced creative generation. Users should approach it as a specialized tool. It excels at tasks like data extraction, classification, formatting, and basic summarization, particularly when the input is well-structured. Attempting to use it for sophisticated analysis or creative writing will likely lead to disappointing results and may require more prompt engineering or retries, potentially negating some cost savings.

Currently available through major cloud providers like Google Vertex AI and Amazon Bedrock, Jamba 1.5 Mini offers developers a scalable, serverless option for integrating its capabilities. Performance benchmarks show a clear leader in speed, with Google Vertex delivering significantly higher output tokens per second and lower latency. With identical pricing across both platforms, the choice of provider hinges primarily on ecosystem preference and the need for maximum throughput. For developers building applications where speed is critical and the tasks are well-defined, Jamba 1.5 Mini presents a powerful and affordable building block.

Scoreboard

Intelligence

4 (29 / 33)

Scores at the lower end of the intelligence spectrum, making it suitable for tasks that do not require deep reasoning or complex instruction following.
Output speed

81 tokens/s

Based on the fastest provider, Google Vertex. Amazon Bedrock is notably slower at 52 tokens/s.
Input price

$0.20 / 1M tokens

Ranks #15 out of 33 models. A highly competitive price for a model with such a large context window.
Output price

$0.40 / 1M tokens

Ranks #12 out of 33 models. Very affordable for output-heavy tasks, complementing its high throughput.
Verbosity signal

N/A

Verbosity data is not available for this model.
Provider latency

0.40 s TTFT

Based on the fastest provider, Google Vertex. Amazon Bedrock has a higher latency of 0.75s.

Technical specifications

Spec Details
Model Owner AI21 Labs
Architecture Jamba (Hybrid Transformer & SSM)
License Apache 2.0 (Open Weight)
Context Window 256,000 tokens
Knowledge Cutoff March 2024
Model Family Jamba 1.5
Intended Use High-throughput classification, RAG, summarization, data extraction
API Providers Google Vertex AI, Amazon Bedrock
Parameters Not specified, categorized as a 'Mini' or small model

What stands out beyond the scoreboard

Where this model wins
  • Massive Context at Low Cost: Its 256k context window is exceptional for a model in this price bracket, enabling long-document analysis that would be cost-prohibitive on other platforms.
  • Exceptional Throughput: With speeds up to 81 tokens/second on Google Vertex, it's one of the fastest models available, ideal for real-time applications and batch processing.
  • Low Latency: A quick time-to-first-token (TTFT) of 0.40s on its fastest provider ensures a responsive user experience in interactive scenarios.
  • Cost-Effectiveness: With input prices at $0.20/1M and output at $0.40/1M tokens, it is extremely economical for high-volume, token-intensive workloads.
  • Open and Accessible: An Apache 2.0 license provides flexibility, and its availability on major cloud platforms makes it easy to integrate and scale.
Where costs sneak up
  • Low Intelligence Overhead: Tasks requiring nuance or complex reasoning may need multiple attempts or more sophisticated prompting, increasing total token usage and development time.
  • The 'Fallback Model' Tax: Because it cannot handle complex queries, you may need to implement a system that routes failures to a more capable (and expensive) model, adding complexity and cost.
  • Large Context Window Trap: While the 256k window is a key feature, using it unnecessarily on every call can lead to higher-than-expected costs, despite the low per-token price. Efficient context management is crucial.
  • Fact-Checking and Verification: Lower-intelligence models can have a higher tendency to hallucinate. Production systems may require an additional verification layer, which adds operational cost and latency.
  • Provider Performance Gaps: While pricing is identical, the significant performance difference between providers means choosing the 'wrong' one for your use case (e.g., Bedrock for a speed-critical app) can lead to a suboptimal product.

Provider pick

Jamba 1.5 Mini is available on leading cloud AI platforms, but performance is not identical across the board. While both Amazon Bedrock and Google Vertex AI offer the same attractive pricing, their performance metrics for speed and latency differ significantly. Your choice of provider should be guided by your application's specific priorities, such as the need for raw speed versus deep integration within an existing cloud ecosystem.

Priority Pick Why Tradeoff to accept
Max Speed & Lowest Latency Google Vertex Vertex is the clear winner on performance, offering nearly 56% higher output speed (81 vs 52 t/s) and almost half the latency (0.40s vs 0.75s TTFT). None. Pricing is identical to Amazon Bedrock, so there is no cost trade-off for the superior performance.
AWS Ecosystem Integration Amazon Bedrock For teams heavily invested in AWS, Bedrock provides seamless integration with services like S3, Lambda, IAM, and CloudWatch for unified management and billing. A significant performance penalty. You will sacrifice substantial output speed and responsiveness compared to the Google Vertex offering.
Lowest Cost Tie Both Google Vertex and Amazon Bedrock offer identical pricing for Jamba 1.5 Mini: $0.20 per 1M input tokens and $0.40 per 1M output tokens. Since cost is not a differentiator, the decision must be based on performance requirements or cloud platform preference.
Simplified Deployment Tie Both providers offer fully managed, serverless API endpoints. This abstracts away all infrastructure management, allowing developers to focus on the application logic. N/A. Both options provide a similar level of operational ease.

Performance metrics are based on benchmarks conducted by Artificial Analysis. Real-world performance may vary based on workload, region, and concurrent traffic. Prices are set by providers and are subject to change. Always verify current pricing with the provider.

Real workloads cost table

To contextualize the cost of Jamba 1.5 Mini, let's examine a few practical scenarios. These examples use a blended price of $0.25 per million tokens (based on the $0.20 input and $0.40 output price, assuming a 3:1 input-to-output ratio for calculation simplicity) to illustrate how affordable the model is for token-heavy tasks.

Scenario Input Output What it represents Estimated cost
Long Document Q&A 150,000 tokens 500 tokens Feeding a large PDF or report into the context window to ask a specific question. ~$0.037
Batch Article Classification 2,000,000 tokens (1000 articles @ 2k each) 1,000 tokens (1000 single-word labels) A high-volume, input-heavy data processing job. ~$0.40
Real-time Chatbot Session 5,000 tokens 1,500 tokens A moderately long conversation with a user, including full history in context. ~$0.0015
Meeting Transcript Summarization 25,000 tokens 1,000 tokens Condensing a one-hour meeting transcript into key bullet points and action items. ~$0.0065
Codebase Context for a Copilot 200,000 tokens 2,000 tokens Loading a significant portion of a codebase to answer a development question. ~$0.05

The takeaway is clear: Jamba 1.5 Mini makes processing vast amounts of text incredibly cheap. Costs for individual tasks are measured in fractions of a cent, making it a powerful engine for applications that need to be constantly aware of large contexts, such as RAG systems, chatbots, and document analysis tools, provided the task itself doesn't require deep reasoning.

How to control cost (a practical playbook)

While Jamba 1.5 Mini is already one of the most affordable models on the market, optimizing your implementation can further reduce costs and improve efficiency at scale. The following strategies are tailored to its unique profile of high speed, massive context, and low intelligence.

Prioritize the Fastest Provider

When pricing is identical, performance is the key differentiator. Choosing a faster provider like Google Vertex has direct cost implications:

  • Reduced Wait Times: Faster responses mean less compute time spent waiting for synchronous tasks, which can be a factor in overall system cost.
  • Higher Job Throughput: For batch processing, higher tokens/second means you can complete jobs faster, freeing up resources and potentially reducing the number of concurrent instances needed.
Be Strategic with the Context Window

The 256k context window is a powerful tool, not a default setting. Avoid waste by treating it as a budget.

  • Use RAG Intelligently: Instead of stuffing entire documents into the prompt, use a Retrieval-Augmented Generation (RAG) system to find and inject only the most relevant chunks of text. This keeps prompts smaller and cheaper.
  • Context Pruning: For conversational agents, implement a strategy to prune the history, keeping only the most recent or most relevant turns of the conversation rather than the entire transcript.
Implement a Model Fallback System

Acknowledge Jamba 1.5 Mini's limitations to prevent wasted calls. A 'router' or 'cascade' system can dramatically improve quality and control costs.

  • Initial Attempt: Route all incoming queries to Jamba 1.5 Mini first. It will successfully handle the majority of simple requests at a very low cost.
  • Quality Check & Escalate: If the output is nonsensical, too short, or fails a confidence check, automatically re-route the original prompt to a more capable (and expensive) model like Claude 3 Sonnet or GPT-4o. This ensures quality without paying a premium for every single query.
Batch Requests for Asynchronous Tasks

For any task that doesn't require an immediate response, batching is your best friend. This applies to things like document classification, data extraction, or generating summaries for a list of articles.

  • Increase Efficiency: Sending many requests in a single API call is more efficient for the provider's infrastructure and can lead to higher overall throughput than sending them one by one.
  • Simplify Logic: Your application logic becomes simpler by managing one large job instead of thousands of small ones, reducing the potential for network errors and retry loops.

FAQ

What is Jamba 1.5 Mini?

Jamba 1.5 Mini is a small, open-weight language model from AI21 Labs. It is designed for efficiency, offering high-speed performance, a very large 256,000-token context window, and low operational costs. It is best used for tasks that do not require complex reasoning.

What is the 'Jamba' architecture?

Jamba is a hybrid AI architecture that combines elements of traditional Transformer models with State-Space Models (SSMs), specifically Mamba. This design aims to leverage the strengths of both: the reasoning and world knowledge capabilities of Transformers and the efficiency and long-context handling of SSMs. The goal is to create models that are both powerful and highly efficient.

What is Jamba 1.5 Mini good for?

It excels at high-volume, token-intensive tasks where speed and cost are critical. Key use cases include:

  • Retrieval-Augmented Generation (RAG): Searching and synthesizing information from large document sets.
  • Data Classification and Extraction: Processing and labeling large amounts of text quickly.
  • Long-form Summarization: Condensing lengthy reports, transcripts, or articles.
  • Real-time Chatbots: Powering responsive conversational agents that need to remember long histories.
What are its main limitations?

The primary limitation is its low intelligence score. It struggles with tasks that require deep reasoning, multi-step problem-solving, advanced mathematics, or nuanced creative generation. It should be seen as a specialized tool for simpler language tasks, not a general-purpose reasoning engine.

How does it compare to models like Phi-3 Mini or Gemma 2B?

Jamba 1.5 Mini competes in the same class of small, efficient open-weight models. Its key differentiator is the 256k context window, which is significantly larger than what most other models in this size class offer. While it may lag slightly behind some competitors on pure reasoning benchmarks, it wins on its ability to process vast amounts of context at high speed and low cost.

What does 'open weight' mean?

'Open weight' means that the model's parameters (the 'weights') are publicly released, in this case under an Apache 2.0 license. This allows developers and researchers to download, modify, and run the model on their own infrastructure, offering more freedom and control compared to closed models accessible only via a proprietary API. However, most users will access it via managed API providers like Google and Amazon for convenience and scalability.

How large is a 256k context window in practice?

A 256,000-token context window is massive. As a rough estimate, it's equivalent to approximately 190,000 words or about 400-500 pages of a standard book. This allows the model to hold the entirety of a very large technical manual, a quarterly earnings report with appendices, or a complete novel like 'The Great Gatsby' (which is about 50,000 words) multiple times over in a single prompt.


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