Phoronix published a review on the Overclocking The AMD AM1 Athlon & Sempron APUs
A quote from the article:
With the initial Linux tests of the AMD Athlon 5150 / 5350 & Sempron 2650 / 3850 out of the way, I ran some basic overclocking tests on all four of these week-old AM1 APUs.Overclocking The AMD AM1 Athlon & Sempron APUs @ Phoronix
To not much surprise given these are $60 USD parts and under, there isn't much to squeeze out of these Kabini APUs with Jaguar processor cores. Many AM1 motherboards reportedly are not even offering any overclocking options from within their UEFI setup area. Fortunately, the ASUS AM1I-A motherboard that I've been using for many of these AM1 Linux benchmarks, offers basic overclocking support.