For Raspberry Pi clusters, ham radio
digital modes, logging infrastructure, or anything where precise
timestamping matters, it’s noise.

A Stratum 1 NTP server solves this permanently: GPS satellites carry atomic-clock-derived time. A GPS receiver with a pulse-per-second (PPS) signal gives you sub-microsecond accuracy. Your entire network syncs directly from that, with no upstream dependency, no internet requirement, no pool latency.

Here’s how to build one for under $20.