While I don't have an ACA 620/630, overclocking requires a hardware modification where the timing crystal is replaced with a faster one. The CPU may tolerate a small amount of speed increase, but often fails within 10% or less of tolerance. Replacing the CPU with a higher rated one may allow further over clocking, but the supporting chips may not. You have to ask yourself one question, "Do you feel lucky?" Or grasp a concept, "Simply put, a 6 ounce sparrow cannot carry a one pound coconut!"
