Prototype performance issues

[uv]

Howdy

Currently playing through Prototype, and I often get drops to ~25 fps where I have visible chug.

The funny thing is, whilst the game is using both cores of my 4870X2, both cores are only at ~40% load, so I've no idea why it's not using both cores to their potential in order to gain FPS.

Surely my Q6600 at 3.2 isn't bottlenecking the game?

Playing at 1920x1200, max settings, 4xAA.

 

[uv]

Are you using a framerate monitor to detect your fps, or are you just guessing because you can see the chug?

Both

Fraps reports dips into 30s often, into 20's intermittently. I can also see the chug

I've yet to buy the whip upgrade - I used it last time I played, and the game was just too easy - I'm now concentrating on drop-kicking choppers out of the sky