There isn't a snowball's chance in hell that you get 40+ FPS in Markarth and overlooking Whiterun...not to mention various other outdoor locations.
Markarth, maybe not. I don't recall. From Dragonsreach however, definitely. I tested that area specifically. And yea, at 1440x900.
I can't blame you for not believing me, I wouldn't believe me either. I'm also rockin' an i5-2500K @ 4.4Ghz, so I'm sure that helps out quite a bit.
I can't show off the FPS in Dragonsreach now, however, as I've modded Whiterun and get about 30-35 FPS there now. Let me see if I can get a screenshot with fraps up for you.