+++ please refer to my user profile about me page and follow my recommendations how to use my mods as an addition to nexusmods terms +++

this mod can be useful for people with older hardware and settings and old setup as i use it. all other users can probably omit this mod.

information updated in aug 2020 due to changes related with more oblivion reloaded features available

the idea
providing useful setup information playing oblivion on win 7 x64 and comparable os combining the best mods and tools for a satisfying, non frustrating playing and modding experience. it works also with win 10 at least on my rig.
your system should provide at least mid range hardware with 8GB Ram and 2GB Vram graphics card. better is 16GB ram and 4 GB vram.
fiddeling with optimized ram settings for a modded dx9 game makes no sense if hardware is limited to 4gb ram and a ram dependend integrated graphics card.
most of the description also works for skyrim while oblivion/obse related settings and tools have to be replaced by skyrim/skse counterparts.

first important advice for all gaming sessions: keep your system clean! avoid unnecessary 3rd party processes running
in windows while reducing mem space and producing instabilities due to
popups or other unpredictable activities  while gaming!
deactivate or reduce  lan and wlan use if you do not need it for gameplay! disable
anti virus and clean up software while gaming! All this stuff may
contribute to a potential risk of ctd or other unpredictable and
unwanted gaming experience!

** update feb2018 tested on win 7 64bit with mod organizer 1.311, oblivion reloaded v6.2.0., enb 0.259  and optional sweet fx 1.5.1 or even better: reshade v3.4 or higher. but be aware: reshade may cause problems with some shader and ini settings, post processing enb effects and msaa**

I had a severe stutter problem before writing this guide even on capable hardware. this guide and the introduced tools may solve
your problem with severe stuttering ingame and handling as it did for me.

tannin's mod organizer 1.311(or newer) should be your solid basis for a new oblivion installation with mods. forget about the alternatives  if
you plan to install complex mods und you dislike to do more than one new game installation. mo is currently the only glich free option (maybe vortex will follow) capable to reach this goal. if you already own a stable system stick to your settings and be happy. you may exit here or you already use mo.
if not this guide will show you one possible and already tested way providing you with a stable oblivion playing and modding experience.
since i use mo i never had to reinstall oblivion again. don't ask me how often i did it before using obmm.
i'm currently running oblivion in mo fully stable with 207 installed mod packages and 141 esp/esm grown since 2015.
mods are installed as downloaded or manually packed zip files in mo while unpacking all included bsa's to have full control in the mo panes how mod files overwrite each other
with the ability to change mod priority simply by changing the esp and/or file load order. no fiddeling or dependency on archive invalidation settings anymore!
unpacking all bsa does no harm, accelerates file loading ingame and let you control all files and their load order in mo if you know what you do
(compare with my nehrim guide and the other mo related paragraphs here in this guide).
if you are unsure and  happy with archive invalidation procedure and automatic installation or your hhd space is limited stick with your bsa's  and some related problems.

oblivion reloaded V6.2.0 (or higher with integrated memory mananging features) is a basic mod because of it's ability to introduce a significant improvement of background terrain and water appearance. the other or options are nice to have, just use them if you like. i recommend purger and gras options ini settings to be disabled (grass shader could be enabled!) to solve stability and performance issues.
equipment option enabled (6.2.0) leads to ctd with my setup with no other equipment related mod installed.j ust use the options you really need and be aware of possible interferences!
oblivion reloaded terrain and water options work safely and they should be always enabled.

enb 0.259 is exclusively uploaded for oblivion to solve graphics related memory problems. it's the only way to prevent ctd in a modded game and to
overcome the ram/vram related limitation of 32bit memory restrictions.
do not use enb 0.181 settings because it does not include this vital feature! it seems that you can use 0.181 enb dll file for this vital setting. read instructions on enboost mod description.

sweetfx 1.5.1 (or the newer reshade) is a nice enhancement/replacer to optimize some basic graphics settings (e.g. replacing game HDR with emulated and faster HDR and bloom) and a configurable smaa feature.  i warmly recommend the unique color RGB vibrance option.
to use sfx together with enb just configure enblocal.ini to use a sfx as a proxy library (sfx d3d9.dll).
be aware that sfx may produce gliches if you do not disable ingame AA (iMultiSample=0 in oblivion.ini) - at least with my nvidia card. instead you can use the sfx integrated performancefriendly smaa. i reached the best compromise with antialiasing results using imultisample=4 combined with 4x sparse grid transparency supersampling (use nvidia profile inspector). but as i said, this may interfere with some sfx/enb post processing options.
be also aware that the included dll files may lead to gliches. delete the (dx11)versions you do not need!



some important info / prerequisites first:
system, game, hardware and version updates change your playing envrionment. it
all may have impact on stability and performance. these side effects are
not covererd here.
oblivion is a 32bit dx9 game with related limitations (4GB memory limit, dx9 related graphics limits).
this description intends to show you some capable tools and a way how to extend these limits for stable modding and playing experience. 
I recommend at least win 7 64bit, dual or quad core cpu, 8gb system memory (more is always better!), graphics card with 2gb built in gddr5 vram
and a fast hdd or even much better a ssd with 100GB or more free space.

badly scripted or very densly populated mods (including mods like "open cities" forcing this state)
may slow down your gameplay as well due to engine limitations. one simple method to get better
frame rates is to "kill" some creatures or to delete clutter in very busy areas. e.g. some
cities in elsweyr can be optimized in this way by neutralizing/deleting
some or all animal creatures caught in cages or clutter not not needed for gameplay.
this will deliver lesser stutter in these areas for sure. 



software needed/recommended (short version):
1. oblivion vanilla installed with 4GB awareness patch for oblivion.exe (4GB patch)
2. obse 2.1 or higher and optionally fast exit 2 because it filters even more annoying ctd messages
3. oblivion reloaded 6.2.0 or newer (grass option, texture purger disabled per ini setting!)
4 stutter remover with manually patched heap setting (obsolete with oblivion reloaded 7.1 added memory managing feature)
5. enb memory patch with enb 0.259 exclusively for oblivion (enables
overriding 4GB memory limit for textures and prevents related ctd)
5b sweet fx 1.5.1. (reshade )install (sfx d3d9.dll as enb proxy library)
6. mod organizer 1.3.11 or higher

mod organizer is the most advanced organizing tool i used and tested so
far. it is not perfect (see installation of obse and oblivion reloaded and obse related dlls but it is as easy to use as any other mod manager) but its a pleasure to use if you are aware of the unbeatable charcteristics of a virtual file system with all its advantages managing your mods to launch oblivion you start obse loader within the already launched mo environment launching obse and oblivion and the virtual mo file system.

enb mem hack and sfx will be lauched automatically within this process if all ini settings are correct.
if the described system is configured and established you will be rewarded with a stable oblivion gaming environment!
you can be shure that no buggy mod will harm your installation anymore. no fiddeling with unintentionally deleted files and overwritten vanilla files anymore.

Installation with comments
1. oblivion vanilla installed with patched oblivion.exe (4GB patch)
...install vanilla and just download 4GB awareness patch and apply it on the oblivion.exe (and no other file)

2. install obse 2.1

3. install or and test if liquid water and terrain shader appears as supposed.
very important if you want to avoid severe stutter in combination with other tools:
a) disable or grass option - believe me, this enabled using denser grass
hurts fps more than using ugridstoload=7 and grass distance set to 16384 with or grass option disabled.
b) disable or automatic purging in OblivionReloadedEsp.ini located in the data\ini folder! automatic purging with default settings leads to severe stuttering while using enb memory
patch and isn't needed using the enb patch. use instead the manual
purge (F12) if you think gameplay slows down.
c) if you encounter ctd while loading or first time after installation be sure to disable at first all options in oblivionreloaded.ini. only terrain and water should be enabled.
it is most likely that a mod conflicts with some of the integrated or features. in my case it was the enabled equipment feature.

4. install stutter remover. it really helps to smooth the game and it replaces the standard memory allocation settings which leads to more
stability. activate heap replacement and select stable option 2 Microsoft, increase heap to 768 (see sr.ini screenshot).
update: if you use oblivion reloaded 7.1 or newer you may drop stutter remover because it includes stutter removing feature.

5. install enb memory patch with enb 0.259 (not 0.181) exclusively for oblivion (enables overriding 4GB
memory limit for textures and prevents related
ctd). the patch works as intended and you do not have to worry about big textures any more if
you own a graphics card with at least 2GB VRAM. configure the ram setting manually for reliable function (see enb description)!
the enb patch will separate the memory used for textures so oblivion.exe is kept small and far away from the 32bit limitation at around 3.3GB.

6. mod organizer 1.3.11 or higher
important recommedation on how to use mod organizer with oblivion:
- obse, oblivion reloaded and obse dependent mods including dlls for the obse folder and own ini's should always be installed manually and before installing common mods via mod organizer - if do not you can be shure to encounter problems and errors while
playing and using other mods using mod organizer. the reason is simple.
at least some dlls in the obse folder seem to be loaded and initialized before mo's virtual file system is established and has gained full control. this leads to unpredictable initalization errors.
to avoid this the only way is to install all game relevant dlls and dll related files like the or shaders in the vanilla data folder before mo
installation.

if you want to load as much as possible via the virtual file system in MO you can separate the non system related parts (all stuff in the data
folder but not dll files, the shaders and all files in the obse folder) from mods like oblivion reloaded (textures, meshes, esp) and install this part as a common mod (zip it and load it via mo).
- make a test that vanilla oblivion, obse an oblivion reloaded work without gliches (e.g. water settings)
before using / configuring with mod organizer.
- tes4edit and tes4all works with mo. just run the related exe within the MO virtual environment.
you will find the new generated files in the mo overwrite folder or if the virtual path already exists in an installed mod in this mod.
if everything runs stable i recommend to zip the generated files as modpackage or add it to an existing mod zip and delete the transfered data in the overwrite folder. then load it as a new package or an update into mo.
if installed you can enable and disable the package in the left pane like any texture mod without physically overwriting anything else.
all vanilla and other mod files are still untouched with this method. this may be extremely useful testing a new mod or a part of it. just activate or deactivate the package you want to test.


uploaded files
i uploaded a ctd-free oblivion.ini setting with ugridstoload=7. maybe it is useful for you, discussion appreciated.
my game runs on an i7, 16GB ddr3 , nvidia gtx 980m win 7 prof x64 with
latest win 7 and nvidia mobile graphics driver updates installed.

it helped me to switch all automatic saving settings  (bSaveOn... )  in oblivion.ini [GamePlay]
section including  bAllowScriptedAutosave in [general] section to 0 ( =0). this means you have to save always manually (F5) but it leads to
much more statbility, lesser stutter and (almost) no ctd ingame. my experience: more automatic saving means more risc of ctd and more
stutter, regardless if you use a fast ssd or a slow hdd. it seems to me to be a gamebryo engine related problem.

additionally i uploaded my oblivion starter batch file, starting oblivion for gameplay incl. oblivion_fullscreen.exe and mod
organizer while killing all unnecessesary 32bit processes incl.
explorer.exe and later on loading again required processes after gaming
session. this batch is an example and should be individually configured
for personal needs.



oblivion ini settings
i did some research on how to prevent ctds (only occuring in exteriors) using uGridsToLoad=7 instead of uGridsToLoad=5 on windows 7 x64 system.
everything else was already optmized (4GB patch, enb settings, esp sequence, unpacked bsa, fast exit2 and so on.
depending on your operating system settings you may set DEP, Admin, XP SP2 compatibility parameters.
playing with uExterior Cell Buffer i tried everything, most stable settings for me:
64, more is possible but probably decrease stability. leave iPreloadSizeLimit at dafault values. changing this value seems to do nothing. high values may lead to slow down or ctd.

i checked the sr_Oblivion_Stutter_Remover.ini and tweaked some settings - but all this stuff should be treated with care and settings depend to some extend on your hardware.
some important safe settings:
more heap may improve your stabilty the more your game is modded. the option 2. (MS heap) is a stable setting . increase it from 256 default to 768 (max 1024) and heap related ctd should be mostly eliminated.

additionally following worked for me if you own capable hardware:

if you own a i5 or i7 cpu with at least 4 physical cores try
[OPENMP]
iThreads=36
iOpenMPLevel=40

[BackgroundLoad]
all bxxx settings to 1 (purge setting 0)
and try
iPostProcessMillisecondsLoadingQueuedPriority=15 (20 default)

[General]
bUseHardDriveCache=1 (or 0) has to be tested  and depends on your hardware

lowering dense grass or other excessive settings may additionally help to reduce stutter.

be aware that you do all these changes at your own risk and  that some ini-settings are hardware and driver dependend and that it is always helpful to make a backup of all relevant settings!

using AA and AF with nvidia card
the only AA settings which seem to work reliable are nvidia Multisampling (4x is perfect for me but it does disable the function of sweet fx and some enb functions) via oblivion.ini setting (iMultiSample=4), driver should be set to "application controlled".
driver controlled modes/settings as override setting didn't work for me. fxaa should be set off.
Anisotropic filtering should be set to 8x or 16x in the driver settings and to 0 in the ini and to off/driver contolled in driver.
you may alternatively use aa settings with sweetfx smaa (iMultiSample=0 in oblivion.ini). this is more perfomancefriendly but not as effective. all sweet fx and enb functions will work.

testing mods and settings
my testscenario included all twmp stuff, elsweyr, some extra world spaces
and all UL-areas. I did extensive fasttraveling and walking and fighting in populated areas with no ctd at all and ugrids=7.
maybe even higer values work with uGridsToLoad=9 but i didn't test this because visual improvement from 7 to 9 is not in relation to the
severe loss of performance and overall stability.

oblivion reloaded (or) is important (in my opinion essential) for nice water, player shadowing, skin and terrain.
i recommend disabling the gras option in or(not the shader!) because it
seem to lead to severe stutter using more dense gras compared to
standard config.
i recommend disabling skin option (only for older versions up to 3)because it may still lead to strange face/skin colors.
V6.2.0 (and even V7 and higher) works fine for me.
i recommend disabling precipitation because it is not or only partly visible under some conditions.
i recommend disabling texture purger options or at least to increase value to 500 or more and instead using enb V0.259 memory patch + F12 to
prevent stuttering. this may reduce some ctd and stuttering, dependening on your hw.
v7 has a memory manager and shadow feature included which replaces stutter remover and shademe and works nice for me.

enb 0.259 with performance speed hack setting (do not use V 0.181 setting, it does not work!) to reduce system memory load and utilization seems to work properly. http://www.nexusmods.com/oblivion/mods/45266/?


system memory and using enb
it is very important to have as much system memory available as possible because hd textures and meshes eat a lot of ram. I recommend at least 8gb ram. Only a max of about 3,5 GB (using 4GB awareness patch) is available in the 32 bit environment, for oblivion.exe and corresponding 32 bit dlls. so be sure to close all not essential applications (including explorer via batch file if necessary). this prevents "out of memory" ctd's.
i recommend to use enb to patch memory. i did additional tests (without enb graphic functions) on that and it works perfectly to reduce size of oblivion.exe in memory. in case you own a 64 bit windows and extra ram , the enbhost process can overcome the 4GB memory limitation of the game graphics engine and win 32bit and reduces by the way memory related ctds and other gliches like slowdowns
in a heavily modded game while using available upper system memory beyond the 32bit 4gb limitation. you have to configure the enblocal.ini with appropriate vram size values (see recommendations for enblocal.ini or in the enb readme).


recommendations

i recommend not to load or run any anti virus related processes and uneccesary, memory eating optional windows services (configure it to start manually or deacivate it) or 3rd party monitoring services while playing. this is mandatory because in a modded game oblivion.exe with ugridstoload=7
may grow up to 3GB and more in the exterior cells while mo needs 200mb. together with all essential windows services this means almost hitting the windows 32bit memory limit. my oblivion would not even start in an exterior cell without 4GB patch. this is not an assumption.
it is tested while monitoring gameplay under different conditions with taskmanager.
because of this more than ugridstoload=7 in a graphically modded game with ultra settings makes no sense!
reducing ugridstoload to standard of 5 means lesser usage of ram and no out of memory related problem should occur. if reducing ugrids be aware of the savegame problem with saved games saved while playing with higher ugrid settings!
if you want to use such saves without ctd load game with high ugrids and reduce ugrids ingame via console and then save the game after reducing the ugrids value.

the other thing is that oblivion.exe utilizes only 2 hardware threads (all game related softwarethreading activated). this means that if you own a quad core cpu you may access the bios hyperthreading option and deactivate the useless or even slower 8 core hyperthreading function!

depending on os settings disabling of data execution prevention and enabling admin rights and xp sp2 compatibitlity settings for all related exe files, except obse under x64 may be necessary for an error/ctd free experience, is recommended

i recommend mod organizer for all playing with more than 5 mods and who hate reinstalling the whole game because of a buggy mod.
in comparison to other tools this is in my opinion the best compromise for a modded game and essential for a heavily modded game. 
it is slightly slower while generating lod with tes4lodgen in the virtual environment in comparison to a standard config but mod handling/uninstalling is easy, safe and stable without the risk to destroy or mess basic settings and data with a buggy mod or mod sequence.
just install your mod and try it. if it does not work just deactivate or delete it and your system is to 100% in the state before the buggy installation. 


my mod warning list related to problems or side effects with other mods leading to reproducable ctd on my rig
- capucines character expansion 1 3b (ctd loading savegames and fast traveling)
- valenwood improved twmp and non twmp version (ctd traveling in some areas mostly sout east maybe due to beta stage and corrupt textures/meshes or simply due to unfinisher areas and beta status and problems with generating lod)


my experience with the bundle of twmp mods
the twmp project was very ambitious but obviously too huge to be realized consequently and without bugs. after testing a lot of configs i must say
i found no config without severe twmp related landscape gliches but with a lot of ctd's and instabilities.
because of this i can not recommend the twmp bundle. i collected and tested all non twmp alternatives dealing with same areas and it runs rock stable. only valenwood improved seems to have beta stage related errors in some areas or an interference maybe due to another mod (elsweyr ?). as an option you may try valenwood unleashed, running stable with one above mentioned instability (and also with some beta related landscape gliches due to the missing south part).


archive invalidation and mod organizer - playing without bsa archieves
i was tired to mess around with more and more texture replacer gliches in my modded game but i love mo as a reliable organizer for my mods including zips (even texture replacers) as sequenced mods. for some unknown reason i've got problems with archive invalidation without finding a simple solution and generally the archive invalidtion method seems to me not a reliable load order method.
so if you have problems with reliability of archive invalidation (texture replacer mods gliches, bsa invalidation,...) and 10GB free HDD/SSD space (not much compared to all the mods installed...) i warmly recommend (tested and it works fine!) to
1.extract even the original game bsa's (mo bsa extractor).
**update** you may remove the original oblivion bsa's but this may lead to instability or crashes if you delete them all. to avoid that at least leave one (dummy) bsa (Oblivion -Meshes.bsa, filled with one mesh) in the data folder! don't forget that!
2. convert the extracted vanilla files with original data folder structure into 3 or 4 zip archives and put these zips as the first installed mods in your mod organizer load order (left pane). (i used four separate zip-archives for textures, meshes, misc and sound).
3. check your work ingame. you should be 100% independent of archive invalidation settings and voila: every new texture/mesh/voice replacer will work reliable and as desired depending on your definded load order. and now you can use mo to see and compare the replaced files including all vanilla ones and you can change load order/priority (left pane the files, right pane the esm/esp) as desired without the need to fiddle with any file dates.
as a side effect this solution may speed up game loading times and reduce additionally some stutter depending on your hardware
4. if you want to have the full control (see what files are overwritten or manipulate single textures/meshes in it) over all mods even unpack all bsa's, zip this stuff mod by mod and load it into mo. you don't need the bsa archive invalidation anymore, instead loading sequence will depend fully on the mod priority and you have full control over the file loading sequence.
5. in most cases and if you own a fast rig with ssd this method (combined with good ini settings) makes stutter remover obsolete. no bsa related loadings lags and archieve invalidtion problems anymore. there is one exception with 3rd person view and a little micro stutter from time to time. this can not be cured by any mod or setting. it is engine related and it still exists in the skyrim 32bit engine.


general considerations
in a heavily modded game there is always a minimal chance for ctd due to mem overload, mod/mesh/texture/script errors, etc.
you can confirm this by playing oblivion while checking the increasing size of oblivion.exe with task manager simultaneously. the maximum size of oblivion.exe with a clean win7 is around 3,2 to 3,5 GB before game freezes with ctd. this available memspace is shortened by any additionally loaded 32bit task including 32 bit windows system tasks. on a 64bit system i advise to use enb memory hack and to use 64bit versions of any process if available to reduce memory usage in the 32bit environment to a minimum.
if you play oblivion with ugridstoload=7 as i do these memory related settings are mandatory for ctd free gaming!

if you find this information useful you may upload and test my oblivion.ini and share your experience and use it or some
parts of it as reference.
if you can provide useful information for this topic please post it!

i wish you all a ctd free gaming experience!