Hitachi P7K500 Specifications - Page 54

5.6 Reliability 5.6.1 Data integrity No more than one sector is lost at Power loss condition during the write operation when the write cache option is disabled. If the write cache option is active, the data in write cache will be lost. To prevent the loss of customer data, it is recommended that the last write access before power off be issued after setting the write cache off. 5.6.2 Cable noise interference To avoid any degradation of performance throughput or error rate when the interface cable is routed on top or comes in contact with the HDA assembly, the drive must be grounded electrically to the system frame by four screws. The common mode noise or voltage level difference between the system frame and power cable ground or AT interface cable ground should be in the allowable level specified in the power requirement section. 5.6.3 Start/stop cycles The drive withstands a minimum of 50,000 start/stop cycles in a 40° C environment and a minimum of 10,000 start/stop cycles in extreme temperature or humidity within the operating range. . 5.6.4 None Preventive maintenance 5.6.5 Data reliability Probability of not recovering data is 1 in 1014 bits read ECC On The Fly correction 1 Symbol : 10 bits No Interleave 34 symbol ECC This implementation always recovers 16 symbol random erros and a 330-bit continuous burst error 5.6.6 Required Power-Off Sequence The required BIOS sequence for removing power from the drive is as follows: Step 1: Issue one of the following commands. Standby Standby immediate Sleep Note: Do not use the Flush Cache command for the power off sequence because this command does not invoke Unload Step 2: Wait until the Command Complete status is returned. In a typical case 350 ms are required for the command to finish completion; however, the BIOS time out value needs to be 30 seconds considering error recovery time. Refer to section 11.0 "Timings," on page 266. Step 3: Terminate power to HDD. HITACHI Deskstar & CinemaStar P7K500 Hard Disk Drive specification (Rev 1.1) 46