Siemens SIMATIC HMI IPC677C Operating Instructions Manual page 76

Commissioning
7.9 Notes on operation
Comparison of Flash drive and hard disk drive service life
Examples of the service life for a Flash drive
With a "Data logger function", a 4 KB file is written to a 1 GB Compact Flash card every
5 seconds. The cluster size is 4 KB in this case. Due to the file segmentation, the file is
always written to another location on the Compact Flash card.
With this example, the Compact Flash card has a theoretical service life of 79.3 years.
Example of the service life for a hard disk drive
The service life of a hard disk drive depends on the following factors:
● Temperature (operating & storage / transport)
● Shock (operating & storage / transport)
● Vibration (operating & storage / transport)
● Humidity (operating & storage / transport)
● Voltage supply
● Power on hours (POH)
● Duty cycle (% workload, i.e. write/read/positioning)
The service life for a hard disk is between 2.5 and 5 years, depending on the factors listed
above.
Booting from the Flash drive
A operating system must be installed before you can boot from the Flash drive. You can read
about the procedure required for installation of an operating system in the section Installing
Windows (Page 150).
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SIMATIC HMI IPC677C
Operating Instructions, 04/2013, A5E02722710-04