Do mods affect performance?

[InuyashaFE]

I've been running Skyrim at 20 FPS outdoors, with a studder, I've tried many performance mods but none of them have done anything substantial. The game still runs like a lawnmower on a treestump.

 

However I don't remember Skyrim running /this/ badly before I modded it, so my question is, do mods in general slow down the performance? Does it depend on the mod? Or does Bethesda simply suck at coding?

[SineWaveDrox]

In my experience, it really depends on the mod. If the mod adds textures with high resolutions, or meshes with extreme detail, there will probably be some performance hit, depending on how demanding the models are, and the graphics capability of the computer. Also, if the mod causes an area to have a large quantity and/or variety of objects, this can cause performance hit as well, again depending on the computer running it. Worst case would be an area filled with a variety of objects which have high detail meshes and high resolution textures, with lots of light sources casting shadows on all of this stuff. Mods with scripts probably have an impact too, but I don't really know much about the scripting system in Skyrim, so I don't know for sure.

[Matth85]

Common sense.

Some mods don't, some do.

 

Why? Because some mods add better resolution, and some mods are dirty and clug the codes. The bigger the mod, the more needs to be loaded at every time.

The kind of mods that risk to slow your game:

 

1) Mods that increase detail level. This one is rather obvious.

2) Mods that have a constant script running. A bad script that runs constantly could slow down everything else.

3) Mods that have tons of scripts. Chances are something is hindering something else here, and this might cause problems.

 

There is also the chance some mods have messed up somewhere, and now the game is having a performance hit constantly. Which would mean a new re-installation.

 

Or does Bethesda simply suck at coding?

They don't suck, they just can't take the time to do the coding correct. Since even in vanilla Skyrim half the codes are causing problems, and the game requries more power than it should. I believe some modders have managed to get rid of the worse though.

[InuyashaFE]

Ah, alright then. So then the best thing to do is look at the script/detail-heavy mods and test how well they run, or even try a fresh install to compare?

 

Thing is, I only use a bunch of small mods, such as house mods or armor mods. The only exception is Skyrim Monster Mod and I don't think it runs any constant scripts... I may be wrong, though.