I have played around some with the voltage, and as far as I can see the "boost clock" tend to go higher when the voltage is +100mv. Max core boost is then 1428 mhz. With just +24mv max core boost is 1390 mhz. I'm now running without increased voltage(+0mv), and have increased the core clock to +220. Max core boost is then 1397 mhz. Think I'll stick with that. So far it seems stable.