I don't know what the heck is going on with my Oblivion game.
Earlier this year I removed the large overhaul mods I was using, ie FCOM being the main one, because I felt like a change and I also wanted to focus my game around Waalx Animals and Creatures which is not compatible with other overhauls. Plus, I was finding playing the game a chore more than a pleasure and got sick of the micro management, so I virtually put the game aside for nearly six months last year except for modding.
At that time, with FCOM, my game ran perfectly with no stutters, no black screens when loading textures or any other problems. I also had Qarl's Texture Pack Redimized as well as a couple of hundred other mods and texture replacers running on the highest settings including shadows etc. All of those together had the potential to cause problems with frame rates, stuttering and/or crashes, but I had none of those. Thank you Wrye for Bash!
Now, for some unknown reason I've had to resort to using an even lower version of Qarl's textures even though you can't really see much difference, turn down some settings and even try Game Booster which is a small program that turns off background processes while you play.
Otherwise, I get a black screen while the game loads a new area for sometimes almost 30 seconds if I fast travel, enter a building or go through any load door. It doesn't always happen which is more perplexing. The only mod I've recently added is Weather - All Natural, which I think is amazing, but these issues were happening before that and hasn't gotten any worse because of it.
I've done all the usual things like defragging my drives as well as game directories, stopped unnecessary programs loading with Windows ie Adobe Acrobat which is a huge memory hog and some others, made sure my graphics card is free of dust, etc, etc. I haven't upgraded video drivers because every other game, including Fallout 3:New Vegas runs perfectly fine and that is heavily modded as well. Playing with the Game Booster makes a big difference but shouldn't be necessary as my Oblivion game doesn't currently have anywhere near the script intensive and heavily overhauled mods anymore.
I'm getting to the severely pissed off stage with Oblivion again because I can't work out what's causing it and some of the little irritations I find with the game annoy me even more than usual. I did work out that one cause was using some clothing and armour mods with very high (unnecessarily so IMHO) textures, but they are rips which explains that little issue. Even having them in my inventory caused the game to slow down to 1 fps let alone equipping them which could take up to 30 seconds or more and then I was unable to move at all. So, I don't use them anymore.
The thought of re-installing the game and configuring it to my liking again gives me the shivers. I'm between a rock and a hard place because I cannot play vanilla under any circumstances and at the moment it's a pain the neck.
Personally, I don't see how it would make any difference to re-install. I know what I'm doing with mods and how to troubleshoot, remove and add them so if it came to having to re-install, other than if I have to re-install Windows for any reason, I don't know that I could be bothered with it. Mostly all I do these days is try new mods, take some screen shots and that's about it. Thankfully there are some awesome mods like WAC and Elsweyr the Deserts of Anequina which has some great quests.
Anyway, I will persevere for the time being and hope to find out what the cause of my problems are.
UPDATE: May 3rd 2011
Well I worked out most of my problems. Too many mods, specifically inactive ones which is a pain because I have different profiles for each character. They have different mod sets according to their history, so if I'm playing a particular character a lot of other mods will be inactive and the limit is around 300-400 including BSA's in the data folder.
Every character also has their own bashed Patch as well so that adds to the numbers. There's no way I'm going to remove all the inactive esps and replace them, as well as sorting my load order every time I change characters.
The other main contributor is\was high resolution clothing and armour that sometimes brought my system to it's knees so I plan to do something about that when I get to it, thanks to a little Gimp tutorial SavageArtistry wrote for me. Who knows I might even get the drive to learn a bit about textures, but I wouldn't bet on it these days. I have a list a mile long of things I want to do for my game, but don't seem to get to to it.