Jump to page content

UptimeMac accuracy issues

I have observed a disturbing and unexplained drift in the UptimeMac uptime reading over extended periods of usage. For example, after about 11 days’ uptime, the uptime clock on my StarMax will be as much as 40 minutes different from the real-time clock. UptimeMac uses the system’s ticks facility to determine how long the OS has been running, which seems to not be very accurate. It is not just UptimeMac, because the stat readout in MacsBug shows the same, incorrect uptime.

It should be possible to remedy this issue using periodic synchronisation with the machine’s real-time clock, although that assumes that the real-time clock itself keeps good time. In my case, the OS regularly adjusts the clock against Apple’s Europe time server, so I can trust the system clock to be correct.

Right now, I am not planning to include any such synchronisation support, but if anyone would like to see this resolved, then contact me and make a feature request.

Return to the UptimeMac page