An information handling system may implement techniques for triggering power loss protection on solid-state storage devices (SSDs) based on PSU pre-warning signals (such as de-asserted POK or VIN_GOOD signals) indicating that power loss is imminent. The pre-warning signals may be provided directly to SSDs over a dedicated connection or may be passed through other components of the information handling system (such as power loss warning logic, a platform controller hub, or a CPU) to a storage controller. The pre-warning signal may be provided to the storage controller as a power loss warning interrupt. This interrupt may cause the storage system controller to issue an in-band message/command to the SSDs or to provide a signal on a dedicated connection to the SSDs in order to trigger power loss protection actions on the SSDs, including switching their power sources and flushing write queues before available hold-up energy is depleted.