General Dynamics Itronix GoBook MR-1 Manual page 82

GoBook MR-1
Primary characteristics of notebook-class HDDs:
2.5" or 1.8" form factor depending on host computer
Power management for extended battery runtime
Parallel ATA (PATA) or Serial ATA (SATA) interface depending on host computer
Shock tolerance (> 300G/2ms operating, 1000G/1ms non-operating)
Enhanced vibration resistance (random and swept sine wave)
Extended temperature range for mobile environments
Storage capacity and access speed required for application
Other types of hard disk products fall short in a mobile environment. Take for example HDDs designed for use in
desktop/server applications. They provide higher storage capacity and faster access speeds than notebook computer
HDDs. But many of these "office environment" designs can only tolerate temperature ranges up to 40°C (104°F),
which can be readily exceeded inside a vehicle on a hot day. They are also typically more sensitive to shock (drop)
events than notebook HDDs. Desktop/server HDDs would quickly fail if deployed in a vehicle or mobile
application.
Itronix GoBook® rugged computers offer additional hardware enhancements that protect your HDD under harsh
conditions. These include shock/vibration damping, advanced system thermal management, and optional hard disk
heaters to quickly bring your HDD to a safe boot temperature in very cold environments. We also pre-configure our
standard Windows software load with optimized power management settings to ensure good system performance
while maintaining product service life.
Expected Service Life
Today's leading notebook HDD manufacturers utilize similar disk usage profiles to calculate expected service life.
For example, the specification for the Hitachi Travelstar 5K100 notebook-class drive states:
Service life of the drive is approximately 5 years or 20,000 power on hours, whichever comes first, under the
following assumptions:
Less than 333 power on hours per month.
Seeking/Writing/Reading operation is less than 20% of power on hours.
[Hitachi Travelstar 5K100 Revision 1.1, December 2004, Hitachi Global Storage Technologies]
Notebook HDDs from other top-tier suppliers have similar specifications.
What does this mean?
Based on standard Windows power management and typical notebook usage patterns, HDD manufacturers calculate
that on average a user will keep their hard disk powered on and available no more than 11 hours per day, and
actively read/write/seek from the HDD no more than 20% of that time. When not actively being used, the rotating
HDD will "spin down" to a low power state and park. Under these normal usage patterns the HDD will provide
reliable service for 5 years.
Obviously, users may periodically exceed these averages. For example, installing a large software suite (Microsoft
Office, Streets & Trips, etc.) will keep the disk active for an extended time. You can think of the HDD rotating
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