Facebook open-source time appliance

I came across this:

Interesting read for this community perhaps.

It’s interesting hardware, but the NTP performance they show (around 40 microseconds) is a bit disappointing. I suspect they didn’t enable hardware timestamping or interleaved mode.

An older Raspberry Pi with ethernet on USB can perform better than that. Here is a test I did some time ago:

With the Mellanox card they used I’d expect the error to stay below 1 microsecond. For example, this is a test with the Intel I210 (one of the few cards that has a PPS input/output):

Several switches would add some asymmetry and jitter, but not as much as they show in their test, so I think there were some software timestamps involved.

If anyone is interested, I have tested a number of other stratum-1 servers. The results are here: NTP server tests.