Performance issue

[zipsi]

Over a long time I got a feeling I should try oblivion again since its a very good game. It used to perform PERFECTLY on XP X64 in any situation, in windows 7 x64 too, but not in combat. Every time I get hit by something, vsynced max 60 fps drops to around 5-6, it is horrible and it ONLY happens when I get hit by someone or fall too much, in 1 word - when I lose health. First I thought its the screen shake, that maybe it had some issues - completely disabled its features in oblivion.ini. Screen is now effectless when I lose health, but lag still spikes hard. I've traveled around lots of forums and none of the results work, some say its the sound of footsteps - caused uber lagspikes on some pc's in combat, nothing works, I've tried everything. Doesn't matter on which graphics settings. Also invisible characters (with chameleon spell or items on) cause extreme lag. And the portal to shivering isles has weird artifacts on it and gives even worse lag. Damnit I can play Crysis on very high graphics settings and I cant normally play /2 less demanding oblivion.

Any ideas?

In case someone thinks its hardware fault:
3ghz quad core, 4 gigs of ram and 8800gts 640 with very high eeprom overclock.

[DM8954]

I'm sure it's not a hardware problem. Part of the problem is that Oblivion came out in 2006 and Shivering Isles (the latest expansion) came out in 2007. Windows 7 didn't come out until 2009. There's just not a lot of support there, since it was designed for Windows XP. I think using the 64-bit version comes with problems of it's own, so both together might be problematic. I'm not sure how to fix it, though, sorry.

If there's an option to run a game in "Windows XP mode" or "32-bit mode" or something like that, you might want to give it a try.

[zipsi]

Well 64bit operating systems use "SYSWOW64" to run 32 bit programs, so that happens passively. Compability modes do nothing and the only way to run "XP MODE" is by a virtual OS, all hardware would get emulated, I couldnt even game it at minimum graphics, maybe oldblivion. There must be some way, Fallout 3 and Fallout New Vegas run 100% smooth, they have the same engine.. it must be some specific feature, effect, shader, sound - that happens during getting damaged... I have no ideas... Atm im just waiting for November when I'm going to buy a new gpu.. which will simply overprocess the glitch and.. most likely overcome the lag. Hopeles..