Cron frequency

[eGullet]

Invision's documentation says that if you want to use cron it should be run every minute. There is one task that actually runs that often: "queue". We are hosted as a Cloud Site at Rackspace, where the maximum frequency of a cron job is every five minutes. In previous versions of IP.Board this worked fine. Anyone know what "queue" is doing that it needs to be run so often?