Embodiments include apparatuses, methods, and systems including a selector. A selection signal may be provided to the selector to select a first synchronization signal as a control signal when the first synchronization signal is available, otherwise a second first synchronization signal as the control signal. The first or the second synchronization signal may synchronize a first or second display content received by a first or second display device with a first or a second display refresh rate, respectively. The control signal may be provided to a controller to control the second display content received by the second display device. Other embodiments may also be described and claimed.