I'm honestly dissapointed by Oblivion's graphics engine. It looks nice, but it's not as amazing as I thought it would be. Considering how crap the framerates are, I really don't recommend buying it for the PC unless you've got a dual 7900s or dual 1900s. Mouse-look and the mouse cursor also doesn't seem to be hardware accellerated, which makes looking around seem particularly laggy.
I've got a AMD64 3700, 2GB of good quality RAM, and a GeForce 6800GT. If you're used to playing games at 40-60 frames per second, Oblivion will seem extremely slow. There are a lot of settings you can turn down, but but the game just looks really dull if you turn 'em down so far that you get consitently high framerates.
I played D&D: Stormwind at high settings at 1680*1050 and the framerates in that game are damn good. So I'm not really sure why the hell Oblivion, which doesn't really look much better than Stormwind, runs like shit. I guess that's what happens when developers try to make an engine look good on the XBox 360...
I would try a few of the tweaks below and experiment with the ingame settings. I hear Vsync is a must to aid mouse lag
hope to get 1680x1050 out of my X800 XT PE !
I will have the game tomorrow and give tweak results on monday. (note I have just grabbed all the tweaks arround a few forums not tested so backup your inis before you try)
In the folder unique to your character (It's somewhere in My Documents My Games for me), edit the Oblivion.ini file in the following ways:
bUseWaterReflectionsMisc=1
bUseWaterReflectionsStatics=1
bUseWaterReflectionsTrees=1
bUseWaterReflectionsActors=1
Set uGridsToLoad = 10 (5 by default)
Change the fLandTexturingTilingMult = 0.5000 (2 or 2.5 by default)
(Note: This does increase load times.)
iFPSClamp=60 "this lock FPS to stope cases of suttering"
buseharddrivecache=0 changed to 1
buseshader30=0 changed to 1. Just in case this means SM 3.0
bdsoundacceleration=1 changed to 0 This made a HUGE difference with onboard sound. (Sigmatel)
bbackgroundloadlipfiles=0 changed to 1
bloadbackgroundfacegen=0 changed to 1
busemultithreadedfacegen=1 left at 1. I'm using a dual core so I would assume this is part of that
bbackgroundcellloads=0 changed to 1
busemultithreadedtrees=1 left at 1. Same reason as before.
busebackgroundfileloader=0 changed to 1
To somewhat fix the water, change this:
uNumDepthGrids = 1 (it's 3 by default).
fGrassEndDistance=3000.0000
fGrassStartFadeDistance=2000.0000