> ## Documentation Index
> Fetch the complete documentation index at: https://docs.primeintellect.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Models

> Which models and GPU types you can dispatch on Hosted Training

The model list is cluster-dependent and changes as models are added, so the CLI is the source of truth:

```bash theme={null}
prime train models
```

That gives you two things:

* **Models** — the models available to dispatch
* **On-Demand Capacity** — purchasable GPU types with their current `$/GPU-hour`, and whether a run **starts now** or **queues**

Add `--output json` for machine-readable output. For pricing mechanics, see [Billing](/hosted-training/billing).

## The weight cache

Runs boot from a cluster-side weight cache and never download weights at start-up. **A model that isn't cached can't be dispatched** — a config naming one fails at dispatch, before any GPU is reserved.

To see only the cached models for a reserved cluster you hold:

```bash theme={null}
prime train models --fft-only
```

If the model you want is missing, [reach out](mailto:contact@primeintellect.ai) to get it added.

## GPU types

To list every GPU type you can dispatch on:

```bash theme={null}
prime train gpus
```

You can pin one explicitly at dispatch with `--gpu-type`, or let the platform pick. Placement favours clusters that already have your model cached, since a cache miss means a full weight download.

## Choosing a model

**Validate first.** Start with the smallest model that exercises your environment end to end — a short run on a small model catches config and reward-function bugs for a fraction of the cost. Keep `max_steps` low and watch that the loss or reward moves at all.

**Then scale.** Once the environment is proven, move to the model you actually care about and raise `batch_size` and `group_size` for a more stable reward signal. MoE models with small active parameter counts give strong performance per GPU-hour.

Size the run with the `[deployment]` block — see [Full Fine-Tuning](/hosted-training/full-finetuning#config) for single-node and multi-node examples.

## Thinking mode

Some model families support a thinking mode that produces extended chain-of-thought before the final answer. It tends to help on tasks that benefit from multi-step reasoning — math, code, logic — at the cost of longer completions, which means more tokens generated per rollout and more wall-clock per step.

Thinking is controlled through the renderer and sampling config; see [prime-rl Configuration](/prime-rl/configuration).

<CardGroup cols={2}>
  <Card title="Billing" icon="receipt" href="/hosted-training/billing">
    How GPU-hours are metered and where rates come from.
  </Card>

  <Card title="Full Fine-Tuning" icon="wand-sparkles" href="/hosted-training/full-finetuning">
    Config schema and dispatch reference.
  </Card>
</CardGroup>


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