Man those temps are good. Are you still using the AC to cool your rad?

Btw, we have the exact same chip. Except mine is the Xeon W3520 version... 3945A906 right?

I've only done a bit of overclocking for now and have a lot more to go, but right now I'm sitting at 206x21 = 4326 mhz / HT on @ 1.344v load, 1.28v vtt I believe. I forget the exact other settings, but they are very close to stock. CPU PLL is undervolted at 1.4v IIRC. I wouldn't call this a 24/7 stable overclock yet as I haven't really stress tested it, but it's been working great for normal everyday usage.