I recently purchased a new X2 4400+ s939, and after some initial problems, I've got it nice and stable now.
If you saw my other posts in the "Building high performance PC" section, you'll know that I struggled to get it stable at stock voltage out of the box. I think it has something to do with the Big Typhoon I put on. After some crazy searching, I found on the DFI Street forums a guy who said that he noticed that when you tighten the Big Typhoon too much, it actualy bends the mobo, and I think that might have caused the problem. I went back to using the stock cooler, and I haven't had a single problem so far.
1. I've lowered the voltages progresively down from 1.4V, to 1.3V (which shows up as 1.28V in the BIOS and Everest Ultimate 2006/CPU-Z), and the CPU is still stable in dual Prime95 for more than 12 hours. I haven't tested it for longer cause I'm just too impatient!
So, does the fact that it's stable at voltages well below stock indicate that it might overclock well, or does it not mean anything?
2. Why is it that a hypothetical CPU refuses to be stable at, let's say, 250x11=2650, but will be stable at 265x10=2650? Does anyone have in-depth knowledge of the internal workings of a CPU to explain it to me? 2650MHz is 2650MHz, isn't it? Why a difference in stability at the same clockspeed?
3. Where can I check the stepping of my CPU against other good overclocks to see if I got a "bad" or "good" stepping CPU?
Okay, that's it for now. I'll eventually put the Big Typhoon back on when I start to overclock, but the stock is doing fine for now, keeping it below 40C under full load.
Your expertise is greatly appreciated!