The emergence of Big Data has led to an increased demand for storage across the entire application and workload spectrum. With the Ultrastar DC HC500 series, Western Digital offers reliable high-capacity hard drives (HDDs) that can manage the significant data growth in data centers. The DC HC500 series is designed for public and private clouds, where storage density and cost-effective infrastructure are critical factors. The Ultrastar DC HC550 HDDs are the unique commercial hard drives featuring Energy-Assisted Magnetic Recording and a Triple Stage Actuator. Together with HelioSeal on a platform with 9 disks, these technologies provide high areal density for all customers and markets.