Pony schedulers default behaviour is as follows:

1. One scheduler per core. 2. Schedulers run one actor behaviour at a time. 3. When a scheduler has an empty work queue, they will steal work from other schedulers. 4. The number of schedulers will scale up and down with the amount of work (but never more than number of cores).

There are various parameters you can change to alter scheduler behaviour should your pattern of use need it.