The SkyrimPrefs.ini is located in Documents\My Games\Skyrim. Make a backup as usual.
Interesting variables are as follows, in order of appearance in the .ini and showing their default settings.
bDoDepthOfField=1
bTreesReceiveShadows=0
bDrawLandShadows=0
bShowFloatingQuestMarkers=1
bShowQuestMarkers=1
bShowCompass=1
bMouseAcceleration=1
fAutosaveEveryXMins=15.0000
FOV adjustment
- http://steamcommunity.com/id/pelagius/screenshot/632982493447867061?tab=all
- http://steamcommunity.com/id/pelagius/screenshot/632982493447865212/?tab=all
- http://steamcommunity.com/id/pelagius/screenshot/632982493447863327/?tab=all
- http://steamcommunity.com/id/pelagius/screenshot/632982493447870656/?tab=all
Comparison of bTreesReceiveShadows and bDrawLandShadows values
- http://steamcommunity.com/id/pelagius/screenshot/632982493449604154/?
- http://steamcommunity.com/id/pelagius/screenshot/632982493449599134/?
- http://steamcommunity.com/id/pelagius/screenshot/632982493449949034/?
- http://steamcommunity.com/id/pelagius/screenshot/632982493449952109/?
For me there was no performance hit having them on, but your mileage may vary. Game was running at 1920x1080 on default High settings, except for 2x AA and draw distances set to 7 for all (I think the object and actor draw distances are lower by default). Specs are:
i5 2500K 3.3Ghz, OC to 4.5Ghz
GTX 570 1280MB OC
GTX 460 SE 1000MB for PhysX
DDR3-1600Mhz RAM, 8GB
Win 7 HP 64-bit