I just purchased a new laptop and decided to install Oblivion on it to see how well it runs. Version 1.0 ran with no problems at 40-60 fps (all settings maxed at 768p) while roaming Cyrodiil. So then I decide to install KotN, SI and all the minor DLC, which updates the game to version 1.2. After I install all the new content and load my save I notice quite an fps hit. With all the content loaded the game runs between 30 and 40 fps where previously I hovered at 60. To confirm the dlc is what caused this I unchecked all the new content and reloaded the save. Now my fps is around the better part of 60 again but it tends to spike into the 40s, 30s, 20s evens the teens and single digits fairly frequently.

Is vanilla Oblivion really this badly optimized? I know my system can handle 60fps, but it seems that simply loading the new content (and updating to 1.2) has given me a huge performance hit. Can anyone give me some advice as to improving my performance via mods, ini tweeks or whatever other methods there are?

System Specs: (Lenovo Ideapad Y400) http://www.lenovo.com/products/us/tech-specs/laptop/ideapad/y-series/y400/

Intel Core i7 3630QM
Nvidia GT 650M 2GB DDR5
8GB DDR3 RAM
Windows 8