Im trying to find out what the physical capabilities of Dolphin actually are, here lots of mixed posts saying it wont handle many users, or the database will be too slow etc...
I have several sites with over 1000 members, all seem to run fine, and all are running off the same dedicated server!
I limit things like chat rooms though, and have tried to restructure the way my sites work for interaction, so its less bandwidth intense.
Found a couple of D7 sites with 3-6k members, they seem to run up to speed... not sure what servers they are on! would be good to find out...
just found it interesting that many of the 'big' sites listed in previous posts have all moved to other scripts...
Apparently D8 is being built for scalability which is so important for a social network script!
I HOPE you can easy upgrade from D7 to D8 though... otherwise....