What heatsink are you running? Stock Phenom? If it's stock, then don't go above 3.8g, about.. just keep an eye on your temps during Intel Burn test. If it goes above 65-70*c then drop the clock down a little and leave it.
There was a youtube vid that I had bookmarked that helped me but I can't find it now. Download HWMonitor to keep an eye on your temps while you are doing this. -you will find yourself using it frequently. I wouldn't trust the dial on the board.. I've read a couple reviews where they smoked the board, on the MOSFET section on a relatively low clock.. -=BE WARNED=- that GD70 board is a nice board, but half of the testers have fried it.
-The easiest way to start is to download CPUz, install it (Very small program), and run it. It will tell you all sorts of info about your current, stock, clock. Your processor multiplier should be 14x or 16x. What that is, is the cpu clock cycle.. When you up that it multiplies the cycles that your processor PROCESSES.. I guess.. It takes your FSB (Front side buss) and multiply it by your CPU Core Mult will give you your clock.
The things you are concerned with here are your CORE VOLTAGE, CORE CLOCK and CORE MULTIPLIER. Here's one of my CPUz shots.
-The following is all done through the BIOS.
For a basic start, slowly up your CPU MULT from 14 to 15, then restart.. then from 15 to 16... Restart... then up it again from 16 to 17... At this point you may reach the limit of your STOCK voltage. it may be a good idea for you to run 2 or 3 cycles of Intel Burn test between your initial runs to get an idea of what is STABLE. The stock Phenom heatsinks are pretty beefy. I have gotten to 3.6 stable on a stock phenom heatsink. You will have to up the voltage SLIGHTLY at this point. run Intel burn test @ 4 cycles to see if it is stable.. If it bluescreens, then you are not stable.
-You basically raise the CPU clock until it will not boot windows. if it doesn't boot then you will have to raise the VCORE or your primary CPU voltage feed. DON'T GO MORE THAN .125v at a time and try to stay away from 1.5v until/unless you have a good water cooling setup or a very good air heatsink.. The main problem with OCing is heat dissipation and our AMD Phenoms don't like the heat.
--Idle temps should be no higher than around 40*c -45*c, and load temps should be no higher than 65*c - 70*c.
-Once the VCORE and MULT increase will no longer yield a bootable OC, it's time to start upping the frequencies of other aspects of the board. Do some research on this first as it gets kind of complicated. This will be the OVER 30% clock range.. Up to 30% OC is relatively easy..
-Do some reading here.. I learned a lot from this thread..