Is anyone else having major issues with graphics slooooow downs?

I have played (and replayed) FE several times on my Sony Vaio. It is not a particularly powerful machine, but by turning off a few of the graphic intensive options, I can get very, very smooth graphics most of the time (maybe a bit slow when many units in tactical combat, but very acceptable).

However, when I run Sorcerer King on the same machine, the graphics struggle badly, coming to an utter crawl at times. In tactical combat with more than a couple of units, it's an unacceptable speed. The graphics move, but the sound effects fire then you see a *very* slow motion animation of the attack or death or whatever.

I have turned off *every* option I can find that is said to improve graphics speed. Even at the very basic settings, the game is borderline unplayable.

Am I missing something? I would not call SK graphics significantly better than FE's, and so I'm puzzled why FE plays very acceptably on this Sony Vaio, whereas SK is not really possible. Thoughts?