Seagate Desktop HDD 500GB 7200RPM SATA 3Gb/s 16 MB Cache 3.5"- Internal Drive Retail Kit (ST3500641AS-RK) 500GB storage capacity with SATA III, 6Gb/s NCQ Interface Seagate AcuTrac servo technology delivers dependable performance Seagate OptiCache technology boosts overall performance by as much as 45% over the previous generation. Seagate Smart Align technology provides a simple, transparent migration to Advanced Format 4K sectors. Best Fit Applications include: Desktop or all-in-one PCs, Home servers , PC-based game systems, Desktop RAID, Direct attached external storage devices (DAS), Network attached storage devices (NAS)