As expected, the CPUs ran stable up to about 3.85GHz on air-cooling. We settled with both CPUs at 3.80GHz. While the 245 did need 1.6000VCore for stable operation, the 240e was able to do so at 1.4300V. Because bootup-voltage is limited to the nominal VCore, some boards are limited in terms of overclocking. Some boards, such as the MSI, offer lower frequencies during bootup to ensure higher overclockability. Regardless of voltage 3.9GHz did boot up, but was not stable. MSI boards also supports Cool and Quiet with higher FSBs, not all boards can do that, so make sure, your board does to reduce power-consumption when overclocked.
Athlon II X2 245:
The Athlon II X2 240e is a bit harder to overclock, because it needs a higher virtual FSB due to the lower CPU-multiplier, but the CPU did not disappoint: