There were many improvements made between the C2Q and 1st gen Core generation, the newer is much more efficient. Plus, if you are talking about a comparison between like a Q9650 vs an i3, they are not direct competitors. You have to compare similar price points, and in doing so you will find that the i3 will beat it's C2D or C2Q competition handily.
Plus, none of the C2D or C2Q CPU's had hyper-threading, that I can recall, which changes a lot. There were no 4c/8t CPU's until Core gen 1.