I wouldn't OC much more than what you can get without voltage boost and/ or very minor voltage boost. It's not that your board isn't an overclocker, it's that any board with a 4+1 or 4+2 power phase is good for casual overclocked. You should be able to at least get 4.2ghz across all six cores, but for longevity I'd really carefully gauge if you should go over that(heat wise). You're CPU is 3.5GHZ and when turbo kicks in, it basically disables 3 cores to attain the 4.1GHZ speed, which means voltage doesn't need to be boosted and heat is minimal. In forcing an OC, you are forcing it across all 6 cores(unless, you disable 3), and so voltage usage goes up and heat significantly raises. I'd say lock all 6 at 4.2 and call it a day. Maybe 4.3 if you don't see a temperature difference and/ or voltage is only marginally raised. Not CPu temp, but temp of your mosfets. Most of these(pre-FX) chipset boards tend to already be hot with FX processors in. At least, the 8-cores ones anyway.