Clock Synchronisation in Industry-standard Computer Hardware

Accurate timing is an essential component for various areas of experimental research. Although expensive capture cards provide accurate time stamps for packets seen in networks, those do not help in synchronising applications or in-kemel processes. We present a moderate-cost approach to provide sub-microsecond accuracy on common PC hardware using custom-built clock card. The synchronisation accuracy is improved several orders of magnitude compared with synchronisation over network and an order of magnitude compared with pulse-per-second signal on a serial port. Clock accuracy does not significantly suffer from a high I/O load on the computer.