Ok - my LOD radius = large
Mesh complexity = 100
Mesh REs = 5m
Text Res. = 60cm
Water effects = High 2x and I use FS Water Configurator (highly recommend it its free too) *water slider settings make a huge difference*
Scenery Complexity = Very Dense
Autogen Density = Very Dense
Special Effects = Medium
My frame rates are locked @ 33 *this was also a big difference - I tried a lot of other settings including 'unlimited' and all
other settings gave me problems - I tried 60, 50, 40, 30, 25, and none give me the results that 33 does...go figure*
the water and frame rate settings can have an adverse affect on terrain textures, your rig is rendering water at whatever level you select
and is trying to give you the locked frame rates at that level, in addition to all the other texture settings you have selected, and it causes your hardware to make sacrifices to meet that FPS lock you have...so it all matters - everything is tied to everything else, FSX is practically a symbiotic organism.
I have reduced in the FSX cfg max buildings and max trees per cell to 900 bldgs and 1100 trees per cell
I use 2 additional file tweaks - 'reduced trees' and 'reduced clouds'
I use REX GEX and FSGenesis
I tweaked texture max load to 4096 in FSX cfg
and followed NickN's XP and FSX configuration tutorial almost to the letter....
I would suggest lowering your water slider one or two notches and reducing 'Special Effects' to Medium - you still get good extra effects and to be honest - I cant tell the difference with mine at med vs high so...
Also - check your Frame Rate lock and lower that setting too
FSX is a different animal on every other rig out there - I've never seen anything so fickle and fussworthy in my life - hence the Lomac re-install