In all my searching I haven't found any difinitive information on Skyrim settings and VRAM usage. I'll speak my peace and then any of you super smart guys (or gals) can chime in to help a brotha out.

You've heard the story before... "I've installed the HD textures for Skyrim and now my game is choppy.."

Fair enough right?

Disabled a bunch of texture mods, some other mods, and really it comes down to VRAM. This was my first experience of hitting the VRAM barrier. After finally coming to terms with that I did research to figure out how to alleviate this without disabling the REALLY nice textures.

Quick history is that I've never had this problem and I try to keep my textures at the 1024 level. Skyrim 2K HD is out of the running. I'm cool with this. I'm not seeing a lot of choppiness, just places like the famous top of the steps of Dragonreach looking out on the town panning becomes kind-of a slide show. Some hitching running full bore on my horse outside. Etc. The places with most of the textures in one view. I get it. Problem is my game used to run fancy smooth and I'm kind-of nit picky as my machine USED to be pretty awesome. Regardless I'm gonna update the video card for one with more ram fairly soon but I'm looking at being poor a little while longer so...

What specific settings alleviate the most VRAM? A definitive guide I believe does not exist for this. Everything I read is based on FPS. Although since the packs release there have been some great suggestions. I'm putting this here to help all the downtrodden in the help to alleviate VRAM before having to >gasp< remove the HD textures and to serve as an additional guide to tweaking Skyrim. Hopefully to help me out as well.

My main operating system is on an SSD with Windows 7 64x with 8 Gigs of RAM. System is fully updated and heavily maintained to be a killing machine. Everything is defragged. (Except the SSD)

Video Hardware is 2 x 1GB Nvidia GTX295 in SLI (Quad Core 3.15 Gz Intel)

Okay so this is what I have assembled so far - what I'm going to try when I get outta work tonight.

First - Delete skyrim.ini and skyrimpref.ini from your \documents\games\skryim folder. This essentially will reset everything. I'll keep backup copies of what I have to tweak. to compare with the newly created and fresh skyrim.ini and skyrimpref.ini

Second - Disable Full Screen AA. I have mine set at 2x with a 16x AF setting through Nvidia. Going to drop the AA completely and moves to FXAA plus reduce AF to 8x.

Third - and this is where you come in - what are the settings that most effect VRAM in Skyrim? Object distance? Grass? What is the most bang for the buck when it comes to VRAM?

Also note that I'm assuming (and I could be very very wrong here) that Shadows are heavily CPU dependent and don't rely on VRAM correct? My system runs 60FPS as long as my VRAM isn't getting destroyed. What I'm saying is I don't need to mess with the shadows right?

And finally if you fine people can't fill in the blanks there is a utility on the Nexus that will log Skyrim for VRAM usage so if I really wanted to spend A LOT of time doing this I could go there to finally figure it out and report back. I'm really hoping someone already has the brain cell retention to have done this already.

Long winded I know but there ya go! I'll report my findings here later. Thanks!

Yes a good start there


Although dropping your AA should have a significant impact on your Vram, AF however shouldn't hurt anything at all, it's just a filtering method which is GPU dependant... and the few tests ran, has no discernable impact on performance worth noting.. so best to leave this at 16x


Object Distance, such as LOD distance draw, Grass does also have an impact but not as significantly, it's rather minimal vram usage. Ugrids is by far one of the most demanding right up there with FSAA. Additionally if you have triple buffering FORCED, this uses a little bit of vram too which is dependant on the resolution your running as well specially if FSAA is being used as well.

Texture compression or resolution is by far the root of it all. If textures resolution exceed what is required, for example i'm seeing some textures that have a 2048x2048 resolution, that used to be 512x512, they would have been better off using DXTC1 or 5 (DXTC3 if there is no alpha) with a resolution of 1024x1024. This would cut down on the vram usage SIGNIFICANTLY at no cost to image clarity much, as the example 2048x2048 texture actually looks "poor" at that resolution, as if they took a 1024x1024 texture and increase it artificially for no apparent reason. True 2048x2048 textures show a much much clearer difference.

But this is the root of it all, fsaa/draw distance are indeed a major contributing factor.... but it's all down to the loaded textures.


My little bit of testing has shown that irregardless of the shadow mode you use, doesn't appear to effect the vram usage... while it's rendered by the cpu is irrelevant too, it does appear to take something just doesn't seem to matter what level of shadow detail you select. Increasing the shadow resolution only seems to make the cpu work harder, doesn't "appear" to effect gpu/vram performance at all.

Here is what I changed on my system (GTX460 1024MB) that is working well for me.

1. Use evga precision to monitor vram usage in multiple areas on skyrim(interior and exterior)

2. Read the nvidia skyrim tweak guide: http://www.geforce.com/Optimize/Guides/the-elder-scrolls-v-skyrim-tweak-guide

3. Here are my current settings in the skyrim launcher:

Resolution 1280x720
Antialiasing 2 samples
Anisotropic Filtering 8 samples
Texture Quality High
Radial Blur Qualiry Medium
Shadow Detail High
Decal Quantity High
FXAA unchecked
Reflect Land, Trees, Objects checked
Reflect Sky unchecked
Object Fade 9
Light Fade 23
Actor Fade 10
Item Fade 7
Grass Fade 7
Distant Object Detail ultra
Specularity Fade 10
Object Detail Fade unchecked

After reading thru the tweak guide to determine many settings that the author did not notice a differemce after lowering them. I decided to start making changes, loading and looking to see if there were noticable changes and there were not. My initial thought was lowering settings would cause a huge graphical loss and was pleasantly surprised when the game still looked beautiful.

Also, the Shadow Detail setting at Ultra caused my system to go over 1024MB of vram repeatedly. So I had to drop it to High. But I do not miss any shadows.

So keep the faith and hopefully these settings of mine will help you out!!!

And what about SSAO? Do yuo think it will impact VRAM usage or is just like any other shadow effect? I'm already using all my VRAM with the hi-def texture packs but I'd really like to try the ssao effect

My GTX570 is starting to struggle with the DLC TP, Skyrim HD, Vurts Flora and extended ugrids 7 ini tweak(everything else max). The 10 FPS drops are what annoys me. Im gonna cut vurts first if the new beta drivers don't smooth it out enough to my liking (and I doubt they will).

I still think most of this is the games/drivers fault. If I alt tab out of the game the chop goes away for a while. Imma try `PCB and see if that has a similar effect, maybe the cell buffer gets purged when I alt tab? This game may be keeping textures in ram too long.

Loling at the thought of a second 570 for skyrim but maybe if I wants the candy will need it.

Thanks guys!

@DHJudas - I wonder if someone will mod the exagerated 2048 textures down to 1024. A mod on the nexus just changing those textures in particular would be fantastic. Also in referencing the Nvidia guide I set AF to it's highest based on performance charts. What is the relationship of VRAM to AF though? Nothing?

@Greynap - I forgot that I had evga precision loaded controlling my fans. Good idea! Thanks for the settings too. Does disabling the reflection of the sky really help I wonder?

@MAC89dPC77TIMES - Well my system runs fantastic otherwise so I know my problem stems from the VRAM iteself as it switches textures in and out from memory in areas heavy with textures or view distance. How much memory is on the GTX570. Texture thrashing is particularly noticeable if you have it. It will be like a slideshow but if you look down it is smooth as silk. I am thinking of a new card as well though. Soon.

Coming away from this a new mod for the texture guys would be replacing the taxing textures with 1024 versions. Call it OPTIMIZED BETHESDA HD TEXTURES maybe?

Generally the hierarchy for memory usage will look like this from most to least impactful:

• 1) Texture size/resolution: the size on disk is the size as the size in VRAM.
  
• 2) AA modes: FS-SSAA > MSAA >= TSAA. FXAA is shader-based post-process AA and does not use any significant amount of VRAM.
  
• 3) Viewport Resolution: this is highly dependent on all other factors and will scale accordingly as resolution increases.
  
• 4) Draw distance/Load distance (ugrids): this determines LOD distance and impacts what textures the engine needs to load/cache in advance of being used.

Biggest impact as most have seen is texture quality/size and it should be apparent why. Skyrim's DDS format for textures is pre-compressed in a DXTC compatible format, so when it is read from disk to VRAM no further compression/decompression is required. The downside is, those textures are still pretty huge even though they're compressed. You can see by looking at the texture BSA files the high-res texture packs are ~3.2GB and the original low-res are only ~1.3GB, so ~3x bigger as a whole. Some of the original low res textures are still used, so excluding those, you are probably looking at 4x larger textures which makes sense going from 512x512 to 1024x1024 or 1024x1024 to 2048x2048 (4x). Not all of the textures need to be loaded at once thankfully, since you have different texture sets for different areas, terrain, armor, etc. Some of the other factors like draw distance/load distance can increase the number of hi-res textures needed as the mip map transitions will be pushed further into the distance. In a perfect world, we'd have 4GB VRAM and the graphics card could store all the hi-res textures locally so no paging to system RAM/disk is necessary.

AA modes require a lot of VRAM because they increase the number of intermediate buffers by sampling and storing color and depth values. Each sample increases the amount of VRAM used for those buffers, generally this can be anywhere from 25-50MB per 1x sample increase depending on the game and scene. Transparency AA can use even more on top of this so the number quickly balloons. You might see a 100MB increase in VRAM going from 2xMSAA to 4xMSAA and another 100MB increase using 2xTSAA on top of that. To compound the issue further, high levels of AA are extremely taxing on GPUs so they can adversely impact framerate as well. While AA is important to image quality, it is probably the first thing I would decrease and rely instead on FXAA which has negligible impact on VRAM.

Resolution generally scales VRAM as you would expect with size, but once you start combining some of the other factors like AA or texture resolution, the impact becomes much greater. For example, AA is going to be much more expensive at 2560x1600 compared to 1280x720 since that AA is being applied to ~4x the number of pixels. Similarly, 2560 with hi-res textures is going to use a lot more VRAM than 2560 with low-res textures. Personally I would not budge from native resolution of your LCD for a variety of reasons, but mainly because LCDs do a pretty poor job of scaling non-native 1:1 resolutions.

Draw distance/load distance tells the game engine what it needs to render in full LOD, so the further you push this value out, the greater load on your GPU, CPU and VRAM. While you do get some nice pictures, especially outdoors in the open world, these settings can be an absolutely performance killer. While I keep draw distance maxed out, I keep ugrids limited to 7 (greater seems unstable).

My general strategy would be this:

• Make sure to close all web browsers/apps that use VRAM prior to launching Skyrim
  
• Set native resolution
  
• Use official highest res texture pack (disable all previous texture packs)
  
• Set draw distance to max
  
• Enable FXAA
  
• Check VRAM usage with AfterBurner or any other monitoring program.
  
• Zone around a bit from area to area to flush/cache new textures. Try to hit cell transitions or pan the camera quickly to see if there is any noticeable stutter/hitching.
  
• If VRAM > 90% of total then stop tweaking if performance is good. If it feels stuttery/unsmooth when panning or transitioning reduce draw distance.
  
• If VRAM < 90% of total, try increasing MSAA, draw distance, or ugrids in small increments. Can also try loading some of the custom textures that weren't replaced by the official HD pack if you have VRAM to spare.

If none of this works and you can't get acceptable performance, you may have to look into reverting to the low-res texture packs or reducing overall resolution. Long-term you may want to look into getting a more powerful GPU with more VRAM (don't get a weak GPU with lots of VRAM).

Actually, any game will dump VRAM when you Alt + Tab out of iy I believe.

Nothing...

@chizow - Excellent! I'm currently running at my native rez of 1680x1050 so that's cool. This is pretty much what I'm doing/going to do. I guess the only the only setting with REAL impact on VRAM in the standard Skyrim config is draw distance? Or is that just the best bang-for-the-buck? That is if I have to mess with it. Hopefully everything else fixes it.

One other thing too. I originally enabled MSAA just to make it so the heat shader wouldn't bleed through walls. I haven't tried it since so hopefully it's been fixed. If not I'm hoping FXAA will. We'll see I guess.

Regardless final thing will be buying a shiny new card.

Thanks again!

You won't believe this but they have actually already done this. It ended up being the default textures in vanilla Skyrim. ^^

Cool. I won't touch it then. Thanks!

I'm detecting sarcasm. I see what you did there.

Alright so I feel a little dumb. What I meant was at the very least extracting those textures from the original .bsa that were upped 4x resolution but didn't look any diffferent and creating a mod for it strictly for optimization.

This did make me laugh though. Thanks for that.

wat?

having just done a test myself..

i took a previously 512x512 texture..... open the now HD DLC version which is currently 2048x2048.... shrunk it to 1024x1024, saved it as a DXTC5 texture, ran skyrim and it looks much better than the 512x512 equivilent.

How much do they "shrink" going from 2048 to 1024? Worth the try ?

Hehe. Just poking. It is my understanding that all the textures are 1024K in vanilla. I'm not sure how you would further want to optimize them without upping the resolutions?

Edit - Okay, I was wrong. They are 512 then. Sheehs, that explains a lot.

Edit 2 - Which means your idea is actually viable good sir.

@Akanaro - I knew I had something, I just didn't know what.

Still laughing though.

Can't wait until you finish this mod and throw it up on Nexus! LMAO! Hurry up!

This place is too much fun. That or I need to get out more.

MSAA will still have a greater impact on VRAM use, but from my baseline config I would exclude MSAA to start. I don't know how much difference the launcher texture settings make, as I've only ever set that to High. Basically I start off with my "must-have" eye-candy, then adjust from there. Normally MSAA would be must-have imo but FXAA makes it negotiable especially when VRAM concerns come into play.

As an example....

lets take a 2048x2048 DXTC1 texture (common compression) which is approximately 5MB in size lets say for easy referrences.
shrinking it down to a 1024x1024 DXTC results in about a 1.33mb... that's a pretty damn significant savings in vram usage


I didn't mean to generalize, some of the textures in skyrim are 512x512, some are 1024x512 (or vice versa) and some are 1024x2048/2048x2048 although much rarer or limited to the dragons or large textured areas such as alduins wall or alduin himself. You'd be surprised how many much much lower resolution textures there are.


I wasn't planning on doing anything related to the hd textures.... sorry .... i'm sure someone can make a script/program that would properly shrink/optimise the files... not sure how perfect it would be though.

Frowny face.

I was just joking man! Thanks for all the info!

Yes reflecting the sky around Riften made a huge drop in fps on my system. With that feature unchecked, fps back up to 50-60.

I might give fxaa a try later this week. Been pondering it for awhile now.

Wow amazing! Do you mind telling me what programs did you use to do that? I usually use nvtools with the bat files found here (just for DXT comp., don't know if can also reduce resolution)
http://forum.worldoftanks.eu/index.php?/topic/33107-program-for-texture-resizing/

The only problem is... how to find out which textures are 2048??

Ambient Occlusion will eat up VRAM too. Huge resource hog, in the way it's implemented in Skyrim's engine anyways. It also doesn't look very good either--I prefer the way it looks with it OFF

Okay so progress. Resetting the ini's and removing all AA has fixed me for the most part. Very minor hitching. Had to reduce shadow resolution from 4096 to 2048 as well. Almost there. Need to tweak shadows a bit more and try to reduce some texture mods. Is there a way to make just the interior shadows 4096? Thanks all! Will update again later.