This value, expressed in gigabit bps, reports the speed a SAN aggregation group had before its most recent speed change, and it's carried as a parameter in the associated speed-change notification. Admins use it, alongside hh3cSanAggGroupCurrentSpeed, to understand the magnitude of a bandwidth change when a trap fires, such as after a member link goes down or comes up. For example, a trap showing a previous speed of 8 alongside a current speed of 4 tells an admin the group's aggregate bandwidth was just halved, likely from a member link failure.