altern wrote:

i've done this in the past, though not using PD/Gem. the tricky part is the robustness of the networking system, not the actual synchronisation (as local-area networking has a typical latency of 1-2ms, even over wireless). to sync more than one pc together you need a client/server architecture, basically, with one pc acting as the master timekeeper and all the others being slave. but then what happens if your master goes down? the others just sit there dormantly...

to solve this issue of robustness, which was a big deal (it was for synchronising three cpus in a travelling roadshow built into a truck trailer: http://www.frey.co.nz/projects/futurefarming which spent most of its time a long way away from me), i built a system where each cpu had the ability to be either server or client. when the first cpu came up it would listen for server pings for a couple of seconds, and if it didn't find one it would assume that it was to be the server so started up and sent out a ping every few hundred ms. then when the next ones came online they'd hear a server ping and so would connect to it as a client. this way if one machine was down the network could reorganise itself.

.. this kind of thing is probably overkill for your situation, but it's something to be aware of, perhaps.