How does the quality of a power supply affect the reliability of HDD operation?
A power supply unit is the most important part from the PC reliability point of view. In its turn, an HDD is the most sensitive to the power quality, the voltage values and stability, among other PC units. Voltage surges and dips large than specified are unacceptable when the load changes. Such instability may result in faults in the circuitry controlling the HDD precise mechanics, causing even serious failures. When buying a power supply unit, always select some excess power, because an HDD current is not stable, and the power supply unit should provide the required voltage in all peak regimes. Also pay attention to the conditions of HDD power connectors. In the course of time, the cylindrical connectors on the cable can wrinkle and will not provide a reliable contact. As a precaution, you may clamp the connectors using an awl to make the connectors sit on the HDD connector pins more tightly.
