I've built my first computer (config below - room to grow/upgrade). I've got it running at 10.5 CPU multipllier at 3.8 GHz. FSB 362 sitting at about 50-53C on Prime95 FFT Torture Test. Seems stable after about 15 minutes. Haven't pushed it to 24 hours yet. I'm using the Arctic Freezer Pro fan you see below. I'm not overclocking the memory (nor raised the DRAM voltage), and the Vcore is set on [Auto] (still tweaking) with CPU-Z showing the Core Voltage to be 1.328V under Prime, and at Idle it sits at 1.36V. 3DMark06 score is 4964 and CPU score is 3377.
Many people have said 4.0GHz is possible, but I haven't been able to get it stable above 3.8. Prime 95 crashes if not other blue screen etc pbs. I've played with Vcore manually and DRAM Core Voltage, and MCH Voltage and PLL Voltage but with no luck at achieving anything I could run Prime65 against. I think some people just get lucky and get a chip out of a batch that will run that fast, and I'm "lucky" to get a chip that will run at 3.8 GHz. That's fast as heck compared to the stock speed and what another dual core would cost that runs at 3.8 GHz stock.