Another is my system powerful enough?

[AnyOldName3]

If you get them running at the same frequency, the i3 and Pentium should perform almost equally in Dolphin. The Pentium will go higher though, and will thusly outperform the i3. You'll also get more control over undervolting with the pentium, so even if you don't get an impressive overclock, you'll be able to make it run cooler.