FPS problems ?

So recently i bought a new PC. I copied interface and addons folders into my new PC's WOW folder.

Coping the files decreased my FPS dramatically, before i had 140 fps on ultra in the main city, but after i copied my old files my FPS tanked to 35 ish. Same thing when i turn off the addons.

Funny thing is after i delete the copied files FPS goes back 140.

What could be the reason?