Synchronizing system resources of a multi-socket data processing system can include providing, from a primary System-on-Chip (SOC), a trigger event to a global synchronization circuit. The primary SOC is one of a plurality of SOCS and the trigger event is provided over a first sideband channel. In response to the trigger event, the global synchronization circuit is capable of broadcasting a synchronization event to the plurality of SOCS over a second sideband channel. In response to the synchronization event, the system resource of each SOC of the plurality of SOCS is programmed with a common value. The programming synchronizes the system resources of the plurality of SOCS.