Board Thread:Questions and Answers/@comment-24588058-20170305074502/@comment-27056410-20170420191917

the closest in show is in the SGA finaly. But the gate is in orbit.

What we do know:

Having an active DHD gives priority (active due to the antartic gate having a DHD)

pagasus gates take priority (due to SGA finaly)

Gate have a power source gives priority (unless another gate has a DHD)(due to russia having a gate and when the DHD was not plugged in SGC gate took priority)

With this info my guess that they would follow the same rules. Other wise it would just activate one of the gates at random.