I got an Intel C2D e6750 that can go to 3.5GHz but it isn't stable, it BSOD after 10 minutes using Orthos. But here's the thing, when I go back to 3.4, 3.2, or even 3.0, I get the same result. I've adjusted voltage all up and down the range and get the same result.
I've done memtest86...