Hitachi 100GB 7200 RPM HTE721010G9SA00 User Manual

Travelstar E7K100 (Serial ATA) Hard Disk Drive Specification

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The drive withstands the following half-sine shock pulse without any data loss or permanent damage. 

The shocks are applied for each direction of the drive for three mutually perpendicular axes, one axis at a time. 
Input levels are measured on a base plate where the drive is attached with four screws. 

The criteria of A-weighted sound power level are described below.

Measurements are to be taken in accordance with ISO 7779. The mean of the sample of 40 drives is to be 
less than the typical value. Each drive is to be less than the maximum value. The drives are to meet this 
requirement in both board down orientations.  

The background power levels of the acoustic test chamber for each octave band are to be recorded.
Sound power tests are to be conducted with the drive supported by spacers so that the lower surface of the drive be 
located 25±3 mm above from the chamber floor. No sound absorbing material shall be used.
The acoustical characteristics of the disk drive are measured under the following conditions:

• Idle mode:  The drive is powered on, disks spinning, track following, unit is ready to receive and respond to 

control line commands.

• Operating mode:  Continuous random cylinder selection and seek operation of the actuator with a dwell 

time at each cylinder. The seek rate for the drive is calculated with the following formula:

• 

Ns = 0.4/(Tt + T1)

•

Ns = average seek rate in seeks/s

•

Tt = published seek time from one random track to another without including rotational latency

•

T1= equivalent time in seconds for the drive to rotate by half a revolution

Discrete tone penalties are added to the A-weighted sound power (Lw) with the following formula only when 
determining compliance.

9800 m/sec2 (1000 G)

1176 m/sec2 (120 G)

Idle

2.6

2.9

Operating

3.0

3.5