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AI, decoded

Are small language models better than large ones for production?

Often, yes — for a specific, well-defined task. A small model that's been tuned for your job can match a frontier model's quality on that job while costing far less, running faster, and being possible to host yourself. The frontier models earn their keep on broad, open-ended reasoning. The mistake is defaulting to the biggest model for everything; the production-smart move is using the smallest model that still passes your evals for each task. Intercom's Fergal Reid told Chain of Thought that Fin has run over 10 trillion tokens in production, and shifting 30% or 50% to a lighter custom model would mean real margin and lower latency.

· Updated · Chain of Thought

Level 4: How AI systems are built · 4.6 Cost, latency and safety basics

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A row of model circles shrinking from large to small; the smallest one that clears the eval line is ringed, beside the words: The smallest model that passes.

In detail

Big models are generalists; production tasks are specific

A frontier model is built to do almost anything reasonably well. Most production features don’t need that — they do one task, over and over. For a narrow, repeated job, a smaller model tuned on that task can hit the same quality as a giant general one, because it only has to be good at the thing you actually run.

What small buys you

Three things the big general model can’t match. Cost: a smaller model can be far cheaper per call, which is why Intercom’s switch of one high-volume step from GPT-4.1 to a tuned smaller model cut spend so sharply. Fergal Reid frames the goal at 43:55: if 30% or 50% of Intercom’s tokens can run on its own lighter model, that is real margin and lower latency. Latency: fewer parameters usually means faster responses, which matters for anything interactive. Control: small enough models can run on your own infrastructure, keeping data in-house and removing a per-token dependency on an outside provider.

When to stay with a large model

Small isn’t always the answer. Open-ended reasoning, tasks with huge or unpredictable input variety, and work where you can’t gather enough examples to tune still favor a frontier model. Knowledge is the hard limit: Liquid AI’s Maxime Labonne says in episode 43 at 36:43 that knowledge depends on parameter count, and distilling into a one-billion-parameter model will never make it as smart as a three-billion one. Small models can be strong on benchmarks. Microsoft’s phi-3-mini, at 3.8 billion parameters and small enough to run on a phone, reported benchmark scores in the range of Mixtral 8x7B, which has about 47 billion parameters, and GPT-3.5. New architectures, like the efficiency-focused designs Liquid AI is exploring, are widening what small models can do — but the rule holds: match the model to the task. Databricks’ Denny Lee puts it as “there isn’t one Uber model for your company. You’re building many smaller models” (episode 22 at 20:47). NVIDIA researchers make the agentic version of the case in a 2025 position paper, arguing that agents mostly run a small number of specialized, repetitive tasks, where small models are sufficient and more economical, with larger models invoked selectively where general reasoning or open-domain conversation is essential.

The decision rule

Don’t default to the biggest model. For each task, find the smallest model that still passes your evals. That’s usually where cost, speed, and quality balance out in production. Small language model vs. frontier model goes deeper on the comparison, and can an open model cut your AI costs? covers hosting one yourself.

Disclosure: Episode 22 aired while Chain of Thought was Galileo’s podcast and Conor worked there (42:47); Databricks, the guest’s employer, is an investor in and partner of Galileo (13:44). Episode 49 was sponsored by Galileo, the Season 3 presenting sponsor (read at 28:52).

Walk down the sizes; ship the smallest model that passes Five models shrink from a large general frontier model on the left to a tiny model on the right, all run against the same eval for one specific production task. The first four pass; the smallest fails, since fewer parameters hold less knowledge. The smallest model that still passes is ringed: that is the one to ship for this task. Below, what small buys you: lower cost per call, faster responses, and the option to host it on your own infrastructure. When to stay large: open-ended reasoning, huge or unpredictable input variety, and tasks where you can't gather enough examples to tune. Fergal Reid of Intercom, episode 49, on moving work to a lighter custom model: cheaper, faster, better. Maxime Labonne of Liquid AI, episode 43: knowledge really depends on the number of parameters. The smallest model that passes Don’t default to the biggest model. For each task, walk down the sizes against the same eval and stop at the last pass. ONE PRODUCTION TASK · ONE EVAL frontier ship this one too small: fewer params, less knowledge pass pass pass pass fail smaller, tuned to the one job WHAT THE RINGED MODEL BUYS YOU Cost far cheaper per call Latency usually faster Control host it yourself STAY LARGE WHEN the work is open-ended reasoning, inputs vary hugely or unpredictably, or you can’t gather examples to tune. Intercom’s Fergal Reid, episode 49, on moving work to “a lighter model, using our own custom model”: “cheaper, faster, better.” Liquid AI’s Maxime Labonne, episode 43, on the floor: knowledge “really depends on the number of parameters.” The rule: the smallest model that still passes your evals, task by task.
An illustration of the rule, not a benchmark: the smallest model that still passes your evals, task by task. Fergal Reid (episode 49) and Maxime Labonne (episode 43) supply the quoted lines. Download the image

Hear it from the guest

“If we can make 30% of those, 50% of those using a lighter model, using our own custom model, cheaper, faster, better, I think it's great, it's real margin, it's real lower latency.”
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“Knowledge is really really depends on the number of parameters, and you can try to squeeze as much knowledge, for example, with knowledge distillation into one b model. It will never be as smart as a three b model. That's a fact.”
“There isn't one Uber model for your company. You're building many smaller models.”

Quotes lightly edited to remove filler words.

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From the conversation

This explainer is drawn from these episodes — each carries its full transcript.

Concepts in this explainer

Small Language ModelKV CacheFrontier ModelModel ParametersLatencyAI EvaluationTokenizationAI Benchmark