AMD A6-3670K overclocking advice

[kingfed]

Hi all. I am new to overclocking and brought a second-hand A6-3670K and GA-A55m-DS2 combination basically to practice on. I have replaced the stock heatsink with a Corsair Seidon AIO 120v before starting. AMD overdrive allows a 3.4GHz overclock, and at present Ive set a 3.2Ghz overclock through the BIOS running stably. I am about to try to overclock the GPU and memory and I think I should do this through the BIOS. I then plan to crossfire it with an HD6450 as recommended by AMD. I'll probably sell the result to my friend for a HTPC/light gaming if it looks like it will be up to it (and then build my own).

I have some questions.

1. Am I right in thinking AMD overdrive just progressively ups the multiplier until the system is unstable? As in it doesn't do anything with the voltages?

2. If the above is correct could I maybe expect a little more performance by adjusting voltages. Is it worth it?

3. When I start upping the GPU settings should I get the most I can out of it, or try the best to match it with the graphics card?

4. Should I go for the 6450 card take my chances and try a higher specification one?

Money not a biggie, getting the most learning out of the build is.

Thanks in advance.

 

[kingfed]

So to update, I had a perfectly stable system at 3.2GHz and increased the GPU to 675MHz without problem. System temps stayed below 40 on HWMonitor. I then pushed the CPU to 3.3GHz and had BSOD. Increasing the voltage one step led to a couple of lock-ups, and then one step further it seems to be stable at present (ran IntelBurn repeatedly and temps are 52 max). I think this will be my limit and the 675MHz will match with a 6570 I hope.