This article describes how many devices can perform an operation in EloView 3.

Currently, up to 5,000 devices may perform an individual operation. In other words, an user may choose to perform an operation, e.g. deploy content or apply OTA update, to a maximum of 5,000 devices at one time. If you need to apply changes to more than 5,000 devices, then we recommend to operate on the devices in batches of 5,000 at a time. 

Please see below for the error messages which appear when attempting to operate on more than 5,000 devices.