First of all: I didnt find a solution for this, even after searching the forum for quite some time.
I am playing in Multiplayer with 2 Humans and rest AI. Full Game, Huge Random Multi Galaxy. The first 1 or 2 hours all works fine. After 2 or 3 hours, the game gets incredible laggy. For the Host (me), this means: every minute or so, the game is stopped for 10-20 seconds (not freezed, more like "paused"). For the Client this means Lag througout the game of about 5-10 seconds.
Our system specs are quite good: Athlon X2 5400+, 4 GB Ram, ATI 3870, Win XP.
As is our internet connection: broadband, DSL 4000 and DSL 16.000 (Downstream: 4 Mbit and 16 Mbit, Upstream: 60k and 80k). Lines are tested and perform well. Same happens while playing by Hamachi.
Theres not a problem in single player for the both of us.
Changing graphical options hasnt brought a solution.
My guessing: The game cant handle hundreds and hundreds of units over Internet?
Any suggestings so far?