Ehm.. what happened? 631 can do 5GHz+ on air.

maybe not a good chip?

not all chips OC that good 5Ghz on ait.

This was on a formula special without Vmod, and 4.9 was the best i get with it.

but got new ones lined up for next round

is it a 37xxA Costa Rica?

I had a couple of those, couldn't even do 3.8 on air

38**A

was bad chip for OC

I see now that the memory is clocked very high, you used 266 fsb strap? Even the worst cedar I tested did 6.9 on ln2, but that was on 333 strap

can also part of the mobo that it didn't clocked well