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

# Engines

> Understanding brightstack engine tiers and compute resources

# Engine Tiers

We have different engine tiers to match your compute and storage needs. Each tier provides different levels of resources and capabilities.

* **Sandbox**: 1CU shared engine for development and testing, no permanent storage.
* **Boost**: Shared engine that can boost up to 8 CUs, great for applications with varying performance requirements.
* **XS (Extra Small)**: 1 CU dedicated engine with unlimited storage, ideal for small production workloads.
* **S (Small)**: 2 CU dedicated engine with unlimited storage, perfect for growing applications and small team analytics.
* **M (Medium)**: 4 CU dedicated engine with unlimited storage, designed for production applications and moderate data processing.
* **L (Large)**: 8 CU dedicated engine with unlimited storage, built for high-traffic applications and intensive analytics.

## Compute Units (CU)

A **Compute Unit (CU)** represents roughly:

* 1 dedicated vCPU
* 8GB of RAM
* 100GB of fast local NVMe storage space (used for caching and query disk spill)

## Storage

All engine tiers (except Sandbox) include:

* **Unlimited storage** backed by object storage
* **Fast local cache** for frequently accessed data
* **Automatic scaling** - storage grows as needed
* **High durability** with built-in redundancy

The local NVMe cache provides high-speed access to your most frequently queried data, while the object storage backend ensures unlimited capacity and data durability.

## Managing Engines

You can create, start, stop, and manage engines using the brightstack CLI:

```bash theme={null}
# Create an engine
bright engine create --name <ENGINE_NAME> --type <ENGINE_TYPE>

# List your engines
bright engine list

# Start an engine
bright engine start <ENGINE_ID_OR_NAME>

# Stop an engine
bright engine stop <ENGINE_ID_OR_NAME>
```

Engines that have been idle for over 10 minutes will be automatically stopped to save costs. You can start them back up anytime you need them.