Well, I've got bad news and good news:
Bad news (as stated by derFunkenstein
): Intel Sandy Bridge processors are overclocked by increasing the CPU multiplier. Because of this, there are processors with a "K" suffix that indicate an unlocked multiplier (aka, they can be overclocked). You have to get into the i5 family before you get processors like the i5-2500K
that are overclockable. Moral of the story, you're not going to get any kind of significant overclock from your i3-2100.
Good news: Intel Sandy Bridge processors run circles around the competition. Even your i3 can outgame AMDs Phenom and FX procesors.
Here's another example.
Enjoy your i3, it's a very solid performer.
i5-3570K, ASRock Z77 Pro4-m, Asus GTX660 TOP, 120 GB Vertex 3 Max IOPS, 2 TB Samsung EcoGreen F4, 8GB G-Skill @1.25V, Silverstone PS07B