Ultrastar DC HC555

1: One MB is equal to one million bytes, one GB is equal to one billion bytes and one TB equals 1,000GB (one trillion bytes). Actual user capacity may be less due to operating environment.
2: Projected values. Final MTBF and AFR specifications will be based on a sample population and are estimated by statistical measurements and acceleration algorithms under typical operating conditions, typical workload and temperature 40°C. Derating of MTBF and AFR will occur above these parameters, up to 550TB writes per year and 60°C ambient (device-reported temperature). MTBF and AFR ratings do not predict an individual drive's reliability and do not constitute a warranty.
3: See http://support.wd.com/warranty for regional specific warranty details.
4: 512e: Advanced Format drive with 512-byte logical sectors. Sector format can be converted to 4Kn by downloading the WDCKIT Drive Utility and following the instructions for Internal Drives.
5: Portion of buffer capacity used for drive firmware.
6: This drive is in compliance with the European Union Directive 2011/65/EU and Directive (EU) 2015/863 on the restriction of the use of certain hazardous substances (RoHS) in electrical and electronic equipment.
7: Based on internal testing; performance may vary depending on host environment, drive capacity, logical block address (LBA), and other factors. The location of the max rate is at approximately 10% into the capacity of the HDD. 1MiB = 1,048,576 bytes (2²⁰), 1MB = 1,000,000 bytes (10⁶).
8: Idle power based on use of Idle_A (=Idle_0). Operating Power: SATA models: Random RW 50/50 8KB QD=1 @40 IOPS, SAS models: Random RW 50/50 4KB QD=4 @MAX IOPS.
9: Operating temperature: 5°C ambient temperature, 60°C device reported temperature.