I am getting the best of my system?

Hi!I am a bit newbie to FS so I wonder if I was getting the best of my system to play FS9.With default scenaries I don't find problems at all.. game runs smooth. But when scenaries add on then my FPS drop to aprox 10.Pentimu IV 2Gz768 RAMchipset SIS650Radeon 9800PE (128 bits)Soundblaster Live!on Settings in FS9 I have all to half except clouds where is everything at minimun with detail clouds.I am using 800x600 config MIPmap 4, Render to texture and not AA.I like to fly online so not AI.I have done many of the tips shown on AVSIM, if not everyone but still have this behavior.Maybe is normal to get this performance with this spec. but maybe not.If you have any ideas to give me I will be very happy.Many thanksNick