I've got my new (post RMA) E8400 in and re-cleaned (see some of my other posts). I've just hit 4ghz at 1.21v as reported in cpu-z (1.25 in bios). Running about an hour stable on Prime95. This seems like a really low voltage, and I'm thinking I've gotten a great chip (other than it reporting 103c for the CPU temp to the bios-grrr). Is a common 4ghz voltage for the E0 chips?