Somewhat correct, but with that framerate difference you are heavily understating it. Without bottlenecking your scenario and result is correct.
HOWEVER. In my case any C2D around less than 2Ghz that is used with the 8800GT (or HD3850; I used it once) gives me rather bottlenecked performance; in game its very noticeable. Once you pump the clocks up to say 3Ghz there is a noticeable gain in performance which nears 10FPS. Depends on the game however games like crysis I got shit all improvement =\.
Ketxxx on the otherhand is totally off in another direction; the HD3850 is NOT a Hd4850 once you boost clocks; sure you may have gained performance within 3D Mark 06; but thats not a game! The HD3850/70 will not attain HD4850 performance even with massive OC. You will only remove bottlenecks!
3D Mark 06 has become a competiton to grapple onto the best way to get a higher score even if its not logical. Anyway 3D Mark scores depend on the two factors the CPU and GPU. Just remember that the GPU score is more heavily weighted versus to CPU score.
Use more than one game. A game engine as inefficient as cryengine 2 isn't really a valid place to base conclusions off
.