Third day in a row I'm struggling to find a way to optimize quality/performance of Skyrim. I'm reinstalling the whole thing second time, so I decided to take my time and post this topic.
My PC specs:

CPU - AMD Phenom II X4 955 AM3, 3,2 GHz
GPU - HD 6870, 1 GB
RAM - 4 GB DDR3, 1600, CL9
HDD - SEAGATE 500 GB, 16 MB, 7200
I have stock cooling + additional casing fan, but I haven't overclocked anything, so I have no overheating issues.

In january I was running Skyrim on ultra settings seamlessly, even with few high quality texture replacers (lite versions) and Realistic Lighting installed. Note, that back then I didn't try any ini tweaking - I could get even better performance.

Now, after installing patch 1.5 and AMD driver v12.4 everything turned into mess. I can't play with my previous settings and mods. I have solid 60 FPS (V-Sync enabled), but in some areas (Solitude, Dawnstar, plains around Whiterun), when I turn the camera around it drops even to <1. It happens ONLY when I turn the camera. I did some tests - reinstalled Skyrim and uninstalled mods - FPS drops when turning the camera were almost unnoticable, but were present.
Note: camera lags don't happen, when I walk around, while looking on the ground.

Do you have any idea what may be causing it? Rendering detailed terrain, shadows, LOD or dynamic depth of field?

The most funny part - installing ANY ENB series mod cuts my FPS in half, be it performance heavy Jasmin ENB or light version of Superb ENB, it has the same effect on performance. By cutting my FPS in half I mean literally - if I have 120 it gets cut to 60, if I have 60 it gets cut to 30. I experienced even heavier performance hit with Sharshooters ENB though. I guess my PC can handle ENB up to Jasmin, but for some unknown reason I lose more FPS than I should, like every ENB must hit the same performance threshold.
Also ENB increase camera lags significiantly.

Do ENB series mods behave like this or is this issue specific for me?


I apologize for any mistakes I've made, english is not my native language.

EDIT: I forgot to mention, that after updates I also have much longer loading times and problem with flickering shadows.

I get lousy performance now after 1.5. Also flickering water and crashing to desktop with no error. Played tons of 1.4 and it was much better.

1.5 added shadows to the grass -- which comes with a big performance hit if added with everything -- try turning off the shadows on grass and things should go back to pre-patch performance levels.

How do you turn off grass shadows?

I had a similar issue to a lesser extent and went back to the AMD 12.1 driver. Noticeable difference for me.

You can't turn them off. http://www.gamesas.com/topic/1370538-grass-shadows-are-buggy-hurt-performance-and-cant-be-disabled/

I made the thread to partly bring up this issue. Feel free to continue the discussion there so perhaps Bethesda sees the thread and reacts to it....

Man... if anyone wants to invest in a headache then buy an AMD GPU and a copy of Skyrim. Prepare to be tweeking ALL the time. Horrid drivers and bad game updates have consumed more of my time than playing the game. Of course, this is largely due to me using mods to make the game pretty... but still. BLARGH!!!!!!!!!!

You can test to see if shadows are causing the problems you have by temporarily turning them off via:

fInteriorShadowDistance=0.0000
fShadowDistance=0.0000
fShadowLODStartFade=0.0000
iShadowMapResolution=1 (setting this to 0 will cause a fps hit)

I know by experience that you will get huge perfomance gains in certain hotspot areas of the game. As for turning off shadows on the grass by ini or CK I have not seen an option to do this yet.

I'm pretty sure that causes lights to become very dark and is therefore a bad idea.
There is a mod that fixes this and turns shadows off properly, but not tree shadows which are the actual problem here.

Things would be a lot better and simpler if Bethesda understood that toggles for heavy graphical performance features, that are even buggy, are necessary.

There is more than one effect at work here. The shadows on the grass tweak does remove one of them, but has no effect on the tree shadow that fall on the grass or the dark/discoloured grass - these are different train wrecks. They messed around a lot with the shadows in the last patch and all the changes are bad.

That said; There is an effect that has very little/no visible quality that is removed by the shadows on grass tweak. Go to the tundra around whiterun with the tweak off and then with it on. I was getting a minimum 10fps improvement with the settings i was using. Unfortunately, it has no effect on the other (arguably more serious) shadow issues and that's why people think it doesn't work.

Are you talking about bShadowsOnGrass=0?
If so, I tried that and I measured FPS. I got saw no FPS difference compared to when I set it to 0, which makes me think it's a leftover .ini setting now broken.

yes, that's the one. are you putting it under [display] in skyrim ini.? it definatly works. i can destroy/restore performace at will by just disabling/enabling the tweak.

Yeah I put it in the right place. I even tried in both .inis. I saw no visual difference and 0 FPS difference.

Curiouser and curiouser. I just did some testing. I hadn't messed with this since i installed my gtx 680 a few days ago - prior card was ati 6970. i have to admit i'm seeing little difference with the tweak now. With the ati card the difference was huge and obvious. Perhaps it's an ati/nvidia thing as to seeing an improvement or not? the effect is definatly there, but right now i'm hard pressed to see it either.

bShadowsOnGrass=0 is set like that by default in the Skyrim.ini and the grass that have shadows on them are classed as trees by the engine and the CK. So any grass ini tweeks won't do anything.