Help! Which CPU is better? i3 540 or i3 2100

The more recent Sandy Bridge Core i-series CPUs (socket 1155) are generally about 10% on average better performing than the older Clarkdale Core i-series CPUs (socket 1156).

Therefore, while both Core i3's have similar clock speeds, the i3-2100's performance should be roughly 10% better on average for games and general applications.
 
We think that the difference between the 1st generation Intel® Core™ processors (like the Intel Core i3-540) and the 2nd generation Intel Core processors (like the Intel Core i3-2100) is closer to a 15% improvement for the new processors at the same speed. There are other areas of improvement such as power going from 73w to 65w on the newer processors and the graphics are better then what was usable on the 1st generation processors. You can see the other differences between these processors at http://ark.intel.com/Compare.aspx?ids=46473,53422,.

Christian Wood
Intel Enthusiast Team