Spring RTS Engine

Hello, When i play spring, i think i have fps problems. map: speedmetal In the begin, i have 400+. When i have alot of nuno's + techplants and stuff, it goes to 100+- When i fire 50nukes at a point, it drops to 10fps? Pc specs: e8400 @ 3.6Ghz 8800GT 2GB RAm. Reso: 1024 Settings: Verylow & low. M...