Very strange lag.

[Gengar]

I don't know if this is something that can be helped, but I'm asking anyway just in case.

This has been happening for a while now, probably since I got the game. It seems to be worsening a bit recently though.

My game runs rather smoothly on high settings. Not perfect, but very playable, and I can live with a few stutters here and there. However even though outside areas are usually silky smooth, interiors have very weird and severe lag spikes, only when looking in certain areas.

An example would be inside player homes (mod-added or vanilla), looking say, southwest (it varies) will slice the FPS down to single-digits, making it nigh-unplayable. Looking away makes it go back to being perfectly smooth. Same happens inside taverns, caves, or dungeons.

Outside is fine. I can have a huge team of followers, all fighting a camp of bandits with arrows and spells flying everywhere, and no problems (except for very minor stutters which are to be expected), but going into an indoor area (with or without followers) results 8 time out of 10 in this weird lag spiking.

Don't really know if it can be fixed, but I'd like to at least know what causes it. After searching on various websites and forums, it seems lots of people have similar problems, but no solutions (or, when solutions are given, they don't apply to my game).

Admittedly, my GPU is a bit old (GTX 260) and I'm about to pull the trigger on buying a new one, which I hope might fix this. But I'm scared to put down the quid for it and then find that the problem persists.

Anyone here have a similar experience? If so, were you able to fix it? Would a newer, better card help it?

Also, being that I don't know what might even cause this, I'm not sure what info I ought to post (mods, PC specs, etc), so if anyone needs any particular info, I'll be more than happy to oblige.

Cheers in advance for any help~

[Nord85]

Well, the first step should be that you first try to assess what's the common factor in the lag situations. Looking if there is fire, smoke, NPCs, shadows etc. within sight when the lag occurs. Or is there perhaps too many small objects to render?

Shadows might well be the culprit since AFAIK they put a relatively heavy burden on the PC. Reducing the shadow map resolution (iShadowMapResolutionPrimary, iShadowMapResolutionSecondary, iShadowMapResolution) in the .iniprefs file helps a lot indoors. These three should be set to same values for max performance. For example, my cheap second-hand HD 3870 and dual-core rig struggled indoors with 2048 resolution shadows, but can handle 1024 resolution with perfect ease. To compensate for the more pixelated look of the shadows, set iBlurDeferredShadowMask higher than the default. I have it at 32, but that may be rather extreme. Something like 10 or 16 could also work, depending on the shadow resolution (the lower the res, the higher the blur). As a side effect, that also helps a lot with the notorious shadow striping problem.

Also, check if you run any high-res texture packs that affect indoors, or any mods that affect lighting. Fancy textures can slow down your game, if every interior is pimped up with them.

If shadows or textures aren't the problem, from now on take a good look every time the lag occurs, and try to notice any similarities between the situations. That way you might be able to discern what's wrong.

Sorry I can't help more, but I hope even this could be of some benefit.

[Khali]

This can probably be attributed to two things, lighting/shadows and/or the amount of textures and meshes your video card is trying to process while indoors. The low amount of video ram on your card is not helping either.

The easiest way to fix this is with a GTX 750. It should work with your existing Power supply and does not require a secondary power cable to use it. The GTX 750 Ti with 2GB of video ram would be a better move for just a tad more money, but your going to need a secondary power cable from your power supply to run one of those.

Beyond the 750's you could look at the GTX 660 Ti or the GTX 770. Keep in mind your going to need a good power supply to run any of these. I would suggest trying to get a card with at least 2GB of video ram.

You did not mention what processor you are using. It might be time to consider upgrading that as well. I would suggest at least a i5 with four cores. More and more games are making use of multiple cores now so I find it hard to recommend anything like a i3 or lesser processor with just two cores because your going to feel the pinch in a year or two and need to upgrade from two cores any way.

AMD has some as good or better cards when compared to their Nvidia equivalents. But the prices for AMD cards right now is crazy due to all the coin miners buying them up so I find it hard recommend even looking at one.

[Gengar]

Thanks for the replies!

I have a feeling it might be the shadows as you both described. I at first thought it was fire effects since it happens often in their vicinity, but discarded that when some fires ran fine and the lag appeared in areas without fireplaces. I will try to tweak the shadows a bit and see what happens.

The processor's fine (I have an i7), so I don't think it'll cause me problems. I do run several texture mods, but I'm diligent about always using 2K textures at the highest, and vanilla resolution where possible.

As for the card, I'm looking to purchase a GTX780 with 3GB of VRAM. If that doesn't help things then I don't know what will. My PSU is 700W, so I ought to be fine, I believe. Really my whole rig is fine, but the GPU seems to be where it's having trouble. I run dual GTX260's, but only use one with Skyrim because it wasn't playing nicely with SLI (all my other games run beautifully), so I'm switching over to a single card setup with a beefier card. My mate has had good luck with this card (his setup is similar to mine) so we'll see.

Mind you, I'm totally useless when it comes to computers, so I wouldn't mind hearing opinions on that sort of setup, and if it will even work.

[Khali]

Your always going to be better off with a better single GPU as opposed to a SLI set up using lesser cards. That being said a GTX 780 3GB VRAM will do you very well. The only cards that are better are the GTX 780 Ti version, Titan, or a Titan Black edition. The rest of your system sounds like its going to be fine for a few years.

So yes, you have found a nice solution to your problem.