does ram speed effect the ability to over clock the CPU?
Not for multiplier increases; HTT increases, yes.
Your C3 stepping chip should be able to do more than you're getting now.
If it isn't, I would say it may not be getting enough volts, or your temperatures are too high.
Basically, the lower the temps, the higher you can clock them using the same volts.
Phenom II chips are generally pretty tolerant of higher volts, so don't be too afraid to increase volts more
just as long as your temperatures don't get too high.
You do not want it to get to 60ºC
At minimum I would suggest you try to make sure it doesn't go too high in to the 50's. But lower is always better.
As in, you can't keep increasing volts unless temperatures are low enough.
Using the same board (M4A79XTD EVO) and CPU as you I could bench 3Dmark06 at 4242MHz and run 24/7 stable at 4GHz with ~1.5V
Highest speed I got the 965 was 4431MHz for Superpi 1M (though it was barely stable enough for it)
My 1090T can clock higher. I can bench stably at >4.4GHz and the highest I got was 4600MHz for superpi - with temperatures around 25ºC
To get my best clocks I set it to use 1.7V in BIOS (the highest this board will allow), though the board does have a vdroop issue and will actually give around 1.66V.
Unless you have a
good watercooling system you probably won't reach that high.
Also, it's not healthy to keep the CPU at particularly high volts for 24/7 usage. I would suggest a ceiling of about 1.55V for 24/7 usage. More only for benchmarks and getting the highest scores possible