I'm playing on a laptop with integrated video card (Ati Mobility 4200 HD). The fog is what kills the framerate, so I lowered the amount of fog by setting this in SkyrimPrefs.ini:
@ENB There are no mods for that, only one which hides the fog by making it transparent but that doesn't make any difference in performance. Could you please make an alternate version of ENBSEIRES without fog?
@ENB Remove only volumetric fog, I'm sure that is the real performance killer. Fake fog, fake snow don't cause any trouble. I'm pretty sure fake particles are just image files with alpha transparency facing the player, so yeah, no issue there.
No, they are not. Almost all particle and fogs in game are textured geometry with depth texture projected to make smooth transitions, that greatly decrease performance, because "soft particles" is slow thing. Shader itself not very big, but amount of such objects on the screen is huge by pixel count, it's known bottleneck of all hardware and scaling very slowly with tech progress. Because of wrong multithreading code of the game this problem more worse, something killing parallelization of rendering.