Optimising Oblivion

Tweaks and tips created and compiled by Ashton to make Oblivion as beautiful as can be.

PLEASE NOTE: This guide has now been superceeded by an all-new version - Optimising Oblivion v2.0

PLEASE NOTE: Part 3 of the guide is now released, covering mods and how to use them, and an extensive list of the best - Optimising Oblivion v3.0


Editor's note. Prechache tweak on page 2 has been updated, if you have previously applied this tweak you need to check the values and add the new settings.

Optimising Oblivion v1.0
Oblivion is beautiful. Like the soft curves of a sleek new case, or the gentle whisper of a powerful video card, it’s the type of game that makes you want to spend quality time with it and whisper to it sweet nothings.

Only, at this stage its performance is arguably related to the canine species.

No problem! We’ve can’t help but fiddle and play to get a smoother and enhanced gaming experience.

It’s early days yet, but this is what we’ve found.

First
The tips and tweaks are a culmination of our own testing and the fantastic community at www.elderscrolls.com/forums

Before you begin set your preferences for distance and graphic levels in game and then exit. Going into the settings menu resets some of what we're about to change in the Oblivion.ini file. Note: turn off ‘Shadows on grass’ and ‘Shadow filtering’ now to remove to big performance killers.

Finally, the configuration file can be found in \My Documents\My Games\Oblivion under your user directory. Back it up before making these changes.

Second
To help measure performance improvements, you can show FPS in game by bringing down console '`' and typing:

setdebugtext 12
tdt

setdubtext is great fun to play with. From this we learned the game keeps texture memory around 256M at all times. Users with 512M cards aren’t likely to see an advantage :p

Third
Disclaimer: This isn't a silver bullet (or arrow, as the case may be). Everyone's machine is different. Your mileage may vary compared to what we've seen, so be sure to try each of these out in relation to your machine and if you don't like the result, simply switch back.

Our testbench consisted of an X2 4400+ with 2GB of memory and dual 7800 cards in SLI.

What we can say after hours of playing with these tweaks is:

a) They make a real, tangible, difference and
b) They are not perfect. The game will sometimes crash on exiting, and other odd glitches may occur. If you have any problems simply copy back the original ini, do what you need to do, and copy back the optimised ini afterwards.

A note on HDR: Oddly the fading grass effect and, it would seem, the ability to take screenshots only work while HDR mode is enabled. If you use AA+Bloom and neither work, you know why!

To enable screenshots, set:

bAllowScreenShot=1    (default 0)

And use the PrintScrn key in game.

Onto the tweaks – we’ve broken them down by looks, performance, and finally mods.

Looks
Oblivion is already hotter than a harem of super models, but there’s more you can do to not only improve the graphics, but boost performance in the process too.

More blood
The essence of every fight, and the marks of your hard won victories, blood is limited to 10 decals and disappears after 10 seconds. Don't they know that blood stains?

fDecalLifetime=1200.0000  (default 10)
iMaxDecalsPerFrame=500  (default 10)

Sets 20 mins and 500 decals. Decals use up bugger all memory, so this is a simple and effective tweak.
Note: if you enter the Video settings in game, fDecalLifetime will be reset to 10, so don't go in there!