I'll be straight, I am new to the modding community however, I have created many successful modded operating systems that I will not comment on, so I am somewhat competent lols. You might want to try to reverse engineer the issue. There are different ways of doing this. The most simple is to start with the unofficial patches and your mod only, and then slowly work your way up to your normal build trying to isolate the cause. Both streamline and Oblivion Stutter Remover are Beta mods, and probably should not be used together. I can assert there is little probability that OSR by itself is the culprit, but perhaps in combination with streamline or perhaps streamline alone. I myself have not needed streamline, have a GTX 460 and G530 dual core cpu, with 8 GB of ram. My suspicions are that streamline and your mod are competing with each unless you know precisely how the original cities were coded and are following the exact principles. Makes sense? In other words, your mod probably contains mistakes, and streamline probably still has some bugs.
The first mod you want to install after unofficial and yours is Streamline. If it fails then, you know streamline is the issue.
At that point, you want to open the steamline mod without the oblivion construction software, and try to walk the algorithm it uses through your mod, in essence do a pretend practice to see how the code will behave as it continues. You should be able to isolate the issue, and patch it yourself
I am currently working Oblivion Visual Overhaul 2013; a complete visual overhaul with 0 FPS increase and tangible visuals.
My main issue which is slowing me down is identifying texture that I see in files, and matching them with their corresponding texture name....without having to go through all the textures.
Wish their was a console command.
Stuck right now on the the chapel steps in Bravil (everything else in Bravil is looking perfect).