I have a Raspberry Pi 2 model B and a RTC (precision 1 ppm) hooked up with, without Internet conneciton. When the RPi is power off is the RTC the responsible to keep the current hour but when the RPi is power on is the system clock which keep the hour.
But, how many ppm has the system clock in the RPi? If the RTC is more accurate than the system clock, is it better to set the RTC hour every x time to the system clock, or does ir reduce the performance of the device?
Thank you in advance