Me and several others have been saying for quite some time that the various .ini "tweaks" floating around (such as the ones in the unofficial tweak guide) are meaningless and do nothing to enhance performance other than the placebo effect (and in some instances they hurt performance - ex. all the background loading settings which are intended for the console versions.. changing these will cause reduced performance and increased stuttering). Several of the values are legacy values not even used by the game - you can easily verify this from the console by typing getini "setting:category"

Just out of my own curiosity I was playing with the console and figured out how to dump the settings which the game really uses

First do the following, ensure that you have an original and unmodified .ini file. You can rename or remove the fallout_default.ini and re-validate via steam to re-download. (if your using mods you'll want to change bInvalidateOlderFiles=1 but don't change anything else)

Rename or remove the fallout.ini and falloutprefs.ini in the falloutnv folder under mygames. Start the game, the launcher will make you re-select your settings. Run the game and load a save. Next press ~ to access the console. Alt-Tab back to windows, and delete the falloutprefs.ini and fallout.ini from my games\falloutnv in order for this to work. Alt-Tab back to New Vegas and from the console type the following:

saveini

Now exit the game. This will dump all of the hidden .ini settings to a fallout.ini file in the my games\falloutnv folder. These are the settings the game actually uses (minus the launcher variables for settings such as anti-aliasing, these will be written the next time you run the game). Note that several settings that the various 'tweakers' say to change are non-existent because they are legacy Oblivion settings the game doesn't even read. Even the popular iNumHavokThreads doesn't exist here, it's called iNumThreads in the fallout games (iNumHavokThreads is what Oblivion calls it. Note, you can do this same dump with Oblivion)

Here are some interesting settings you'll find:

iHWThread6=5
iHWThread5=5
iHWThread4=5
iHWThread3=4
iHWThread2=4
iHWThread1=4
iRenderingThread2HWThread=1
iRenderingThread1HWThread=0
iAIThread2HWThread=4
iAIThread1HWThread=3

I played around with these and didn't notice anything change, but my best guess (and I'm not an expert, this is only a guess) is that these values might lock threads to CPU affinity? If that were the case, on an i5 or i7 with hyperthreading, you wouldn't want to tie up 0 and 1 since that's the same core. Again, I have no clue if that is even what this means. Note the two settings for AI threads.. that probably means the threadedai setting does nothing except perhaps disable multithreading ai when you turn it on. Or maybe it's off by default as not to tie up thread 4 which is in use by the HWthread settings, I have no clue!

The other interesting settings have to do with RAM and I haven't played around with them. Despite the tweakguide saying to change ipreloadsizelimit and the interior/exterior buffers - this has no positive effect on memory and should be left alone. The exterior buffers will raise on their own if you mess with the ugridstoload setting. These have nothing to do with cached RAM, whoever said that clearly took a bad guess at what they did

Here are some real memory settings:

[BudgetCaps]
bIncludeWaterInMNumberCalculations=1
uActorMemoryBudgetCap=10485760
uCityLODBudgetAdjustment=5242880
uWastelandLODBudgetAdjustment=20971520
uLoadedAreaNonActorMemoryBudgetCap=185597952
fMaxMsUsagePerFrame=28.0000
fMsHavokTriCount=0.0010
fMsDecalCount=0.0010
fMsLightCount=0.0100
fMsLightExcessGeometry=0.0100
fMsWaterCount=0.1000
fMsTriangleCount=0.0001
fMsGeometryCount=0.0100
fMsEmittersCount=0.0100
fMsParticlesCount=0.0010
fMsAnimatedObjectsCount=0.0500
fMsActiveRefCount=0.0500
fMsActorRefCount=0.2450
fMsRefCount=0.0210
uHavokTriCountInterior=5000
uDecalCountInterior=500
uLightExcessGeometryInterior=5
uLightCountInterior=10
uWaterMemoryInterior=10485760
uTextureMemoryInterior=104857600
uGeometryMemoryInterior=10485760
uWaterCountInterior=10
uTriangleCountInterior=100000
uGeometryCountInterior=1000
uEmittersCountInterior=50
uParticlesCountInterior=5000
uAnimatedObjectsCountInterior=50
uActiveRefCountInterior=100
uActorRefCountInterior=20
uRefCountInterior=1000
uHavokTriCount=5000
uDecalCount=500
uLightExcessGeometry=100
uLightCount=10
uWaterMemory=5242880
uTextureMemory=20971520
uGeometryMemory=5242880
uWaterCount=10
uTriangleCount=100000
uGeometryCount=1000
uEmittersCount=50
uParticlesCount=5000
uAnimatedObjectsCount=50
uActiveRefCount=100
uActorRefCount=20
uRefCount=700

Anybody want to be brave and mess with any of these? Like I said, I messed with the HWthread settings and didn't notice anything at all

One more thing I wanted to add, you can change any of these settings in-game from the console by typing setini "setting:category" value similar to how you type getini outlined in my above post. You cannot change launcher settings like resolution or anti aliasing though, only what is present in the .ini dump

I messed with the memory settings above (I doubled all the values for all items) and it made no difference on performance or RAM usage