Since 2.30 I have only constantly about 14-22 FPS on duststorm and escort (no matter where I'm looking at). While on other maps like street of fire and crossroads I still have my normal framerate (40-130 FPS). And it seems that FPS is dropping by time. System specs: Core2Duo E7200@2.53GHz AMD 4850 WinXP
same probs here with 2.3. didnt have fps probs before and i didnt change hardware or settings, just updated empires.
I found the cause. It's "tracer_1" particle effect that doesn't die for whole round. At the end of crossroads game I had 3200 tracer_1 effects being simulated.