"Richard B. Gilbert" <[EMAIL PROTECTED]> writes: >David Woolley wrote: >> Richard B. Gilbert wrote: >> >>> The clock in a PC is basically the guts of a cheap "Quartz" watch. It >>> wouldn't surprise me if the manufacturers bought the crystals rejected >>> by the watch makers. I suspect that the clock exists MOSTLY so the >>> machine will have the correct date for things like letters and checks. >> >> That describes the RTC, and may not even be valid for HPET systems. The >> clock that ntpd disciplines is not based on a 32kHz watch crystal, but >> on a much higher frequency crystal. Historically, the primary purpose >> of the latter crystal is to provide a logic clock for the processor and >> memory, not for time keeping.
>And it probably varies in frequency with temperature and age. And >probably no one cares if the frequency is off by a percent or two, >especially if it's off on the high side. Who is going to complain if >his 2.4 GHz processor is actually operating at 2.45 GHZ?? And from experiment it is actually off by less than .01%.(100PPM) Most commercial computers are that good. In fact if they are off by .05% ntp is useless and will refuse to even try to discipline it. _______________________________________________ questions mailing list [email protected] https://lists.ntp.org/mailman/listinfo/questions
