From my understanding on a non-K model Intel® Core™ processor the most that you can overclock them is about 4 bins higher. So on the Intel Core I3 2100, you might be able to reach up to 3.6 GHz which would put it closer to the performance that you have gotten out of the Intel Core I3 540 at 4.0Ghz OC’ed. The question was how would an Intel Core I3 2100 stand up to an Intel Core I3 540 overclocked up to 4GHz? In that case the Intel Core I3 540 would have higher performance.
Christian Wood
Intel Enthusiast Team