[H]ard|OCP has an excellent article on Unreal Tournament 3 performance using 6 different graphics cards (8800 GTX, 8800 GT, 8800 GTS 320 & 640, HD 3870 and HD 3850). The article is a great read and is very informative, but the best part is the information on UT3's framerate smoothing option that is only changeable through the game's UTEngine.ini file.
The first option, bSmoothFrameRate, is responsible for keeping framerate peaks down to lessen the spikes in performance. Ostensibly, this is done to make the gameplay feel smoother. We wanted to know exactly how much it affects performance, and if there is any good reason to disable it. To test it out, we set it to FALSE and re-ran the Apples-to-Apples test on our trusty GeForce 8800 GTX."
Notice how with the option turned off (yellow) you do get much higher framerates that are not limited to 62, but the framerate is also much more erratic. There is a 70FPS difference between the highest and lowest framerate on that yellow line. Then look at the blue line and notice how little the line swings up and down. That line indicates a much smoother playing experience.
I have played a lot of UT3 and I did not know about this option until now. I can honestly tell you that I am very pleased with how smooth and pretty the game is and I will not be changing this ini option. In closing I would like to leave you with this quote from the last page of the article:
"The FPS smoothing feature was interesting, and further proves how important it is to look at gameplay performance experienced from video cards rather than raw average framerates in comparison. Just because a certain video card may produce overall higher framerates (the 8800 GTS/3850/3870 in this evaluation) doesn’t mean they are inherently faster. With FPS smoothing enabled the GTX resulted in what looks like slower framerates, but those framerates were smoother. It is now time, more than ever, to concentrate on real-world gameplay experiences delivered by video cards rather than looking at average framerate bar charts to compare performance."