For testing I first ran the benchmarks I commonly use to check out the stability and performance of a system. I ran the tests at stock clock of 2.8gHz, then at my overclock of 3.528gHz. For comparison, I thought that it would be interesting to compare the X3 720 to the Phenom II X4 940 AM2, just to see how an X3 compares with an X4. The X4 was run on the aforementioned ASRock AOD790GX/128 with an MSI Radeon HD 4830 so we really aren't dealing with apples to apples, but I wanted to give some kind of idea how the Phenom II X3 compares to the Phenom II X4. Since the motherboards are basically the same chipsets with different different memory (integrated graphics are not being used on either board), so the benchmarks that aren't video card intensive mostly show CPU differences. Generally the tests in this first battery of benchmarks are not affected by the video card anyway.
Testing showed definite performance gains from overclocking the X3 720. The X4 940 beat the X3 720 at stock clock in most cases, but less so when the X3 was overclocked. I expected the X4 to clearly outperform the X3 in the purely CPU related tests, and it did, but not as much as I thought it might.