One solution to slow frame rates with FSX is to cut back on autogen. Some users cut off autogen because the ‘Sparse’ setting is more than the highest setting in FS2004. Another option is to adjust the slider defaults.Open the FSX.CFG File, and add this entry, just below the [TERRAIN] section in FSX.CFG
The figures above are the default and you should set them to a lower amount. Setting to 0 for instance will mean that you see no objects in the simulation. Please note that the maximum setting for each item is 6000 and it is suggested that you use a minimum of 10 to avoid issues within the game.
The suggested settings to set initially are:
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