TALPA strides forward

"""Then maintaining nanosecond-accuracy time sync between several computers is needed, which is not trivial."""

It is actually really easy if you are not using Cisco switches. The latency of the switches makes a big difference.

Use ptpd from the linux hosts:
http://ptpd.sourceforge.net/

It will allow you to keep nanosecond time sync of all machines in a lan using multicast.