ULTRASTAR C10K1800 900GB 10000RPM SAS 12GB/S. HGST delivers best-in-class performance and capacity in one small form factor hard drive. The Ultrastar C10K1800 is a 10K RPM enterprise-class HDD that stores up to 1.8TB of data, 50% more capacity than prior generations, plus delivers best-in-class active and idle power efficiency, enabling next generation data centers to keep pace with digital data growth and improve space and power efficiencies. Data center architects can also leverage best-in-class performance on the C10K1800, achieving up to 2.5X better random write performance and 23% faster sequential performance over prior generation 2.5-inch SFF 10K RPM HDDs for demanding 24x7 enterprise workloads.