Engineered for the highest quality the ultrastar 7k4000 is put through grueling design tests during development and must pass stringent ongoing reliability testing during manufacturing ultrastar 7k4000 delivers by reducing downtime eliminating service calls and minimizing tco features 20 million hours mtbf up to 4 terabytes of capacity advanced format 512 byte emulation 512e 6gbs sata interface dual stage actuator dsa and enhanced rotational vibration safeguard rvs for robust perfo