I'm playing with the High settings for a "maximum" frame rate and all I've noticed compared to the Extreme settings are :
- No interior shadows
- No real 3D ocean waves, flat water
- Small 3D objects disapear closer (Clipping)
- General 3D objects details degradation closer (LOD)
- Something else ?

I'm looking for console commands to force the interior shadows on. but there is a large number of variable to test and it's very difficult without the possibility to make real time tests in the console, most of the commands are protected and disabled, even with "con_restricted=0"...

All I can do is adding those commands directly in an autoexec.cfg and reboot the game to test, it's not convenient...

For the ocean waves "sys_spec_water=2" works, but it's a general modification of a whole number of variables, not really indispensable.

Here the list af all commands :
http://www.fpstime.com/wp-content/uploads/2011/03/Crysis_2_commands.txt