TAI had no effect at all, as said there?s no one there.
TSCR command gave me 3 extra FPS - but this time the difference was from 28FPS -> 31 FPS, so boost was merely +10% from all the scripts in the whole damn game.
I disabled Alive Waters (my mod lists is basicly from last spring) and Enhanced Vegetation, which together with Streamview settings being low - depending on where I looked - gave me that extra 10FPS. If I turned around and started running it was only 20FPS immeaditely.
I still feel there?s something that?s over-stressing my CPU, making the performance drop sharply the instance something happens.
Yes, CPU, since disabling something purely CPU bound DOES give a boost, even a small one, I know the low FPS problem is CPU-procesing related.
SkyCaptain
Are you using Diverse Waterlife try disabling that and see if fps goes up any,
Vsync not turned on by accident is it?
I tried disabling Alive Waters, as said, which seems to account for a small FPS loss. Might keep that disabled and possibly update to Diverse Waterlife later.

I have Vsync disabled from both the launcher setting and Control Panel. The FPS fluctuates like hell as well. I usually actually keep it enabled, but disabled it just for this troubleshooting to see the real FPS limit.
it could also be as Corepc suggests, or maybe even that you're one of those unlucky fellows who get a disproportionally huge FPS hit from RAEVWD.
I reinstalled RAEVWD two days ago, I had an old version manually installed. Cleaned it out with Oblivion Mod Remover, deleted the DistantLOD folder, and installed the OMOD version without any city or architecture options.
I tested the performance before and after - nothing, no effect at all. If there was, the fuctuating FPS between 17-19 hid it.
I dunno, I?m starting to fear it?s some set of bad meshes or something that I have installed manually. Or some codec problem - I have, in the end, messed around with video codecs lately when trying to make previe movies and such...to bad I have no idea what I should use or should not. I have KLite pack, but using the "reset to defaults" settings makes me unable to watch almost anything.