Instance types?

When you launch an instance, the instance type you choose determines the hardware of the host computer. Each instance type offers different levels of compute, memory, and storage, and is grouped into an instance family based on these features. Choose an instance type based on the needs of the application or software you plan to run.

Redundant Web Services (RWS) dedicates some host computer resources, like CPU, memory, and instance storage, to a specific instance. An RWS instance shares other host resources, such as the network and disk subsystem, with other instances. If each instance tries to use as much of a shared resource as possible, they each get an equal share. However, if a resource is underused, an instance can use more of it while it’s available.

Each instance type offers different minimum performance levels for shared resources. For example, instance types with high I/O performance have a larger share of shared resources, which reduces I/O performance variance. For most applications, moderate I/O performance is sufficient. However, for applications needing higher or more consistent I/O performance, consider an instance type with higher I/O performance.