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:
C:\Documents and Settings\username\Application Data\Microsoft\FSX
Please also see regarding FSX performance tips.
Article ID: 555739 - Last Review: 14 Feb 2017 - Revision: 1