Elder Scrolls IV: Oblivion Tweak Guide
[Page 9] Advanced Tweaking (Pt.2)
bDSoundHWAcceleration=1 - If set to 1, uses hardware acceleration (i.e. your sound card) to reproduce audio. This provides the best audio quality, however if you are having problems such as odd crashes, you can try a value of 0 to disable hardware sound acceleration.
bMusicEnabled=1 - If set to 0, turns off all background music. This will detract from the atmosphere of the game, but can noticeably improve stuttering on some systems, as background music dynamically loads throughout the game.
bSoundEnabled=1 - If set to 0, turns off all sound effects, but does not affect music. This would be an extreme way of gaining performance or reducing crashes and is not recommended for anything other than troubleshooting purposes.
fMainMenuMusicVolume=0.6000 - The main menu music volume can't be adjusted anywhere in the game, except by using the Master Volume slider (which then affects all sound/music). To alter the menu music volume independently, change the value here.
iMaxImpactSoundCount=32 - This option determines the maximum number of channels used for different sound effects. Reduce it 24 or 16 to remove some of the sound effects in return for a performance boost and stuttering reduction. Note however that this setting can crash your system if set too low, particularly with hardware acceleration enabled.
[Memory, Loading & Multithreading Variables]
All users should implement the Memory and Loading tweaks (with appropriate values) below, but the Multithreading tweaks are best used on Dual Core or HyperThreading CPUs.
bPreemptivelyUnloadCells=0 - If set to 1, this setting attempts to unload cell data it thinks you won't need. This can help those with less than 1GB of RAM, however with 1GB or more of RAM, I recommend leaving it at 0 for greatly reduced stuttering.
bSelectivePurgeUnusedOnFastTravel=0 - If set to 1, this option removes a range of unnecessary data when you Fast Travel to another location. This can help keep memory usage down for those with less RAM, so it is recommended such people set this to 1, otherwise leave it at 0.
The above option relates to background loading to attempt to smooth FPS and reduce stutter. I recommend setting it to 1. This may increase some transitional loading times (e.g. loading cities, crossing indoors/outdoors), but should generally reduce random loading stutter as you wander around. If you experience any problems, set them back to their defaults.
Update 2: As of the 1.2 Patch the following loading-related settings have been added to the Oblivion.ini file:
I'm not certain of what the above settings do, but they seem to relate to the loading of post process effects such as HDR which are applied after a scene is rendered. By changing these values you can fine-tune the way their loading impacts on stuttering in the game world. I tried various values, but the most noticeable impact was reducing the iPostProcessMillisecondsLoadingQueuedPriority value from its default of 20 to a lower value, such as 5. It will depend on your particular system as to whether changing this will have the same impact.
[Cell Visibility/Loading Variables]
Importantly: To improve distant textures, particularly the blurry land textures, it is strongly recommended that you instead use the Landscape LOD Replacement Mods as detailed in the Patches & Mods section of this guide on Page 4. These mods provide far less of a performance decrease for a similar effect, and don't result in the types of glitches which altering the uGridsToLoad variable can bring with it.
The above settings when combined can be used to increase the visibility of distant trees. Increasing the uGridDistantTreeRange setting by itself has no visible impact. Yet if you also increase the uGridDistantCount value as well, you will start to see trees further out towards the horizon, on mountain ranges for example. Very high values will reduce performance and dramatically increase level loading times. For example experiment with a value of 200 for both to see the image quality and performance impact on your system, though I would recommend you leave these at their default for the best performance/image quality balance.
The above settings work in much the same way as uGridDistantTreeRange and uGridDistantCount except they apply to tree visibility within cities.
fLandTextureTilingMult=2.0000 - Decreasing this value can reducing the obvious tile pattern which occurs on land textures, but unfortunately also distorts textures close to the character. You can also use this mod for a much better fix to grass tiling.
The next page continues the .ini tweaks.