RouterOS clock, or RouterBoard clock? What about a $2,000 SuperMicro server (X86)?

Still the same. The Mikrotik RouterOS does not handle PPS.

"Typical GPS Performance Since the deactivation of the Selective Availability program on May 2, 2000, most GPS receivers now produce a 1 pps output with a standard deviation of 10 ns or less. Many receivers produce frequency with an uncertainty of < 1 x 10-12 when averaged for one day. Two key...

however, it should be 1 if its coming from a GPS device. . No. A GPS device should only be Stratum 1 if its sending PPS (Pulse Per Second) and from what I've read so far the RouterOS does not support PPS. Mikrotik only uses NMEA so even though its from a GPS, Stratum 4 is probably as high as it sho...