Jamba 1.6 Large (non-reasoning)

A fast, open model with a massive context window.

Jamba 1.6 Large (non-reasoning)

Jamba 1.6 Large from AI21 Labs offers exceptional speed and a vast 256k context window, but at a high price and with lower-tier intelligence.

256k ContextOpen LicenseHigh SpeedHigh PriceText GenerationAI21 Labs

Jamba 1.6 Large is a recent addition to the growing field of open models, developed and served by AI21 Labs. It enters the market with a distinct and somewhat contradictory profile. On one hand, it boasts two headline-grabbing features: a massive 256,000-token context window and impressive generation speed. On the other, these strengths are offset by significant drawbacks, namely a very high price point and a low score on intelligence and reasoning benchmarks.

The model's architecture is its most defining technical characteristic. Jamba is a hybrid, blending the established Transformer architecture with a State Space Model (SSM) based on the Mamba design. This combination aims to capture the best of both worlds: the power and expressiveness of Transformers, which excel at complex reasoning, and the efficiency and linear-time processing of Mamba, which is ideal for handling extremely long sequences of text. In theory, this allows Jamba to efficiently manage its enormous context window without the quadratic scaling costs that would make a pure Transformer of this size prohibitively slow and expensive to run.

Performance benchmarks highlight this trade-off. With a median output speed of over 50 tokens per second, Jamba 1.6 Large is one of the faster models in its class, making it suitable for real-time, interactive applications. Its time-to-first-token (TTFT) is also a respectable 0.85 seconds. However, its capabilities are sharply limited by its low intelligence. Scoring just 14 on the Artificial Analysis Intelligence Index, it lands in the bottom decile of benchmarked models, far below the average of 33. This suggests it is not a good fit for tasks requiring nuanced understanding, complex instruction-following, or factual accuracy.

The final, and perhaps most critical, factor is cost. Jamba 1.6 Large is priced at a premium: $2.00 per million input tokens and a staggering $8.00 per million output tokens. This makes it significantly more expensive than the average open model, which typically costs around $0.56 for input and $1.67 for output. This pricing strategy positions Jamba 1.6 Large as a specialized tool. It is not a general-purpose workhorse but a high-speed, long-context specialist for developers who can absorb the high operational costs in exchange for its unique capabilities.

Scoreboard

Intelligence

14 (28 / 30)

Scores in the bottom tier for intelligence, making it unsuitable for complex reasoning or nuanced tasks.
Output speed

50.7 tokens/s

Ranks in the top quartile for speed, delivering a fast experience for real-time generation.
Input price

$2.00 / 1M tokens

Significantly more expensive than the class average for input tokens.
Output price

$8.00 / 1M tokens

Among the most expensive models for output tokens, a major cost factor.
Verbosity signal

N/A

Verbosity data is not available for this model in the benchmark.
Provider latency

0.85 seconds

Offers a responsive time-to-first-token, enhancing the user experience in interactive applications.

Technical specifications

Spec Details
Model Owner AI21 Labs
License Open
Architecture Hybrid (Transformer & Mamba SSM)
Context Window 256,000 tokens
Input Modality Text
Output Modality Text
Primary API Provider AI21 Labs
Input Price (AI21) $2.00 / 1M tokens
Output Price (AI21) $8.00 / 1M tokens
Median TTFT 0.85 seconds
Median Output Speed 50.7 tokens/s
Intelligence Index Score 14 / 100

What stands out beyond the scoreboard

Where this model wins
  • Massive Context Window: Its 256k context window is exceptional, allowing it to process and analyze entire documents, codebases, or long conversations in a single pass without truncation or complex chunking strategies.
  • High Throughput: With a median output speed of over 50 tokens per second, it's well-suited for applications requiring rapid text generation, such as interactive chatbots, live content creation, or fast API responses.
  • Fast First Token: A low latency of 0.85 seconds means users see a response almost immediately. This is crucial for maintaining engagement and a fluid user experience in interactive scenarios.
  • Open License: The open license provides flexibility for developers and organizations to use, modify, and build upon the model with fewer restrictions than proprietary alternatives, fostering innovation and customization.
  • Specialized Architecture: The hybrid Transformer-Mamba architecture is specifically designed for efficiency with long sequences, a key advantage when fully utilizing its large context window and a differentiator from pure Transformer models.
Where costs sneak up
  • Extreme Output Token Price: At $8.00 per million output tokens, generating text is exceptionally expensive. This can make any task involving significant generation, like summarization or creative writing, financially prohibitive at scale.
  • High Input Token Price: Even at $2.00 per million input tokens, feeding the model its large 256k context becomes costly quickly. A single full-context prompt costs over $0.50 before any output is even generated.
  • Low Intelligence for the Price: You are paying a premium price for a model that scores in the bottom 10% on intelligence benchmarks. The value proposition is poor for any task requiring reasoning, accuracy, or complex instruction following.
  • Penalizing 4:1 Price Ratio: The 4:1 output-to-input price ratio heavily penalizes generation. Workloads that involve summarizing or transforming large inputs into smaller outputs are more cost-effective, but still expensive overall compared to other models.
  • No Provider Competition: Since Jamba 1.6 Large is currently only benchmarked on AI21 Labs' platform, there is no marketplace competition to drive down its high API costs. Users have no alternative for a lower price.

Provider pick

Choosing a provider for Jamba 1.6 Large is straightforward, as it is exclusively available via API from its creator, AI21 Labs. This lack of competition means users are subject to a single pricing and performance standard. The decision, therefore, is not which provider to use, but whether the specific profile offered by AI21 Labs aligns with your application's needs and budget.

Priority Pick Why Tradeoff to accept
Speed & Context AI21 Labs The only available provider, offering excellent native performance and full access to the 256k context window. Extremely high cost and a very low intelligence score for the price.
Cost-Effectiveness Not Recommended Jamba 1.6 Large is one of the most expensive open models available. Other models offer a much better price-to-performance ratio. You lose the 256k context and must switch to a different model entirely, like a Mixtral or Llama variant.
Reasoning & Accuracy Not Recommended The model's intelligence score is in the bottom 10% of benchmarked models, making it a poor choice for tasks requiring logic or precision. Requires selecting a more capable, often proprietary, model like those from OpenAI, Anthropic, or Google.
Simplicity & Direct Access AI21 Labs As the sole provider and creator, integration is direct with no need to compare different API implementations or pricing structures. You are locked into their high pricing and specific performance characteristics with no alternatives.

Performance and pricing data are based on benchmarks conducted by Artificial Analysis. The blended price assumes a common 3:1 output-to-input token ratio. Your actual costs and performance may vary based on your specific workload, prompting techniques, and API usage patterns.

Real workloads cost table

To understand the practical cost implications of Jamba 1.6 Large's pricing, let's model a few common scenarios. These examples illustrate how the high input and output token costs accumulate. Pay close attention to how the cost of generation-heavy tasks compares to input-heavy ones, and the significant expense of utilizing the model's full context window.

Scenario Input Output What it represents Estimated cost
RAG Document Query 100k tokens 500 tokens Querying a large PDF or knowledge base loaded into context. ~$0.204
Long-form Summarization 50k tokens 2,000 tokens Condensing a lengthy report into an executive summary. ~$0.116
Chatbot Conversation 3,000 tokens 1,000 tokens A moderately complex multi-turn conversation with history. ~$0.014
Code Generation 1,000 tokens 4,000 tokens Generating a complex function or class from a short prompt. ~$0.034
Full Context Analysis 256,000 tokens 1,000 tokens A 'needle in a haystack' test across its entire context window. ~$0.520

The takeaway is clear: Jamba 1.6 Large is expensive across the board. Even tasks that seem input-heavy, like RAG, become costly. Generation-heavy tasks are almost prohibitively expensive for production use at scale. The cost of using its primary feature—the massive context window—is substantial, with a single full-context prompt costing over 50 cents before any output is even generated.

How to control cost (a practical playbook)

Given Jamba 1.6 Large's premium pricing, managing costs is paramount for any application considering it. Its unique cost structure, with a heavy penalty on output tokens and a high base cost for input, requires a specific strategic approach. The following strategies can help mitigate expenses and ensure you are using the model for tasks where its unique strengths justify the cost.

Prioritize Input-Heavy, Output-Light Tasks

The model's 4:1 output-to-input price ratio makes it crucial to design workloads that minimize generation. Ideal use cases involve feeding the model large amounts of context to get a small, specific answer.

  • Classification: Classify a long document based on its content.
  • Extraction: Pull specific entities or facts from a large text.
  • 'Needle in a Haystack': Find a specific piece of information within a massive context.
Leverage the Large Context for Batching

Instead of making many small API calls, batch multiple tasks into a single prompt that utilizes the 256k context window. This can be more cost-effective than the overhead of multiple separate calls, especially if you can structure the prompt to produce a concise, aggregated output.

  • Example: Instead of asking for 10 summaries of 10 documents separately, combine all 10 documents into one prompt and ask for a single, bulleted list of key takeaways from all of them.
Implement Strict Output Token Limits

The $8.00/1M output token price is a budget killer. Always use the max_tokens parameter (or its equivalent in the AI21 API) to set a hard ceiling on the number of tokens the model can generate. Without this, a runaway generation could lead to unexpectedly high bills. Be precise in your prompting to encourage brevity and reduce the need for verbose answers.

Use a Cheaper Model for Routing and Drafting

Do not use Jamba 1.6 Large for simple or general-purpose tasks. Employ a cheaper, faster model (like a small Llama or Mixtral variant) as a router. This router model can handle simple queries itself and only pass on tasks that absolutely require a massive context window to Jamba. This 'cascade' approach reserves the expensive tool for only the jobs it can uniquely perform.

FAQ

What is Jamba 1.6 Large?

Jamba 1.6 Large is a large language model from AI21 Labs. It is distinguished by its hybrid architecture (mixing Transformer and Mamba/SSM components), a very large 256,000-token context window, and high generation speed. It is an open license model, but is primarily accessed via a paid API from AI21 Labs, where it carries a high price tag and demonstrates relatively low performance on intelligence benchmarks.

What is a hybrid Transformer-Mamba model?

It's an architecture that combines two different AI designs. Transformers are excellent at understanding complex relationships in data but become computationally expensive with very long sequences. Mamba (a type of State Space Model or SSM) is highly efficient at processing long sequences in linear time but may not have the same reasoning depth as a Transformer. A hybrid model like Jamba aims to use both, leveraging Mamba's efficiency for long-context processing and the Transformer's power for reasoning, creating a model optimized for large-scale inputs.

How does Jamba 1.6 Large's performance compare to other models?

Jamba 1.6 Large has a mixed performance profile:

  • Speed: It is very fast, with an output of over 50 tokens/second, placing it in the top tier for throughput.
  • Context: Its 256k context window is among the largest available, a key advantage.
  • Intelligence: It performs poorly, scoring in the bottom 10% of benchmarked models. It is not suitable for complex reasoning, math, or coding tasks.
  • Price: It is one of the most expensive open models on the market, both for input and especially for output tokens.
What is the 256k context window good for?

A massive context window is ideal for tasks that require understanding a large body of text at once. Use cases include:

  • Document Analysis: Analyzing long legal documents, financial reports, or scientific papers without needing to split them into chunks.
  • Retrieval-Augmented Generation (RAG): Loading an entire knowledge base or multiple documents into the context to answer questions with high fidelity.
  • Extended Conversations: Maintaining context over a very long chatbot conversation without forgetting earlier parts.
  • Codebase Analysis: Ingesting large parts of a software project's code to answer questions or suggest modifications.
Why is Jamba 1.6 Large so expensive?

The high cost is likely a combination of factors. First, running a model with a 256k context window requires significant memory and specialized hardware, which is expensive to operate. Second, as the sole provider, AI21 Labs can set its own price without competitive pressure. The pricing may be intended to position the model as a premium, specialized tool for enterprise clients who need its specific long-context capabilities and are willing to pay for them.

Is Jamba 1.6 Large a good choice for my application?

It depends entirely on your priorities. Jamba 1.6 Large is a good choice if and only if your primary, non-negotiable requirement is a massive context window combined with high generation speed, and you have the budget to support its high operational cost. It is a poor choice if your application requires high intelligence, factual accuracy, complex reasoning, or if you are operating under a tight budget.


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