This "Degradation" is perfectly normal.
You're stress testing on the "low" end of the vcore needed for stability, and many (apparently not all, but a lot) CPU's wind up losing some of the lowest vcore ceiling from when they are new, or first run at a certain overclock, and slowly need a little higher vcore than initially. This not "abnormal" degradation, but seems to be normal with these chips. Going from 12 hours, to 3 hours, to 35 minutes to a BSOD, is a common symptom.
The chips usually settle after a certain point and remain stable long term. I was able to do two 4.5 ghz 1.260v primes for 12 hours twice, after having degradation when it used to prime at 1.236v, to the point where it would BSOD within 30 seconds at 1.236v (originally ran for multiple hours). This was caused by gaming and stress testing at 5 ghz, 1.404v-1.428v. Hopefully all the voltages will settle down and 5 ghz will need 1.440v game stable (too hot to prime test there now) and 4.5 ghz will even out at 1.260v and not degrade further (any more degradation would be caused by 5 ghz voltages, IF the chip isn't broken in/settled yet, which I'm hoping it will be).
Maybe I'll do some bad company 2 for a week, at 5 ghz, then do a 12 hour prime run a week later and see if it still passes at 4.5ghz, 1.26v or if it bsod's...
And repeated prime testing is fine as long as your voltages aren't too high and you keep the chip cool. You're getting into danger land if you prime > 1.4v unless you have some very good cooling.
well you were correct....the 4.5ghz @ 1.29v was working great...then after about 5 hours of having WOW running and surfing the net and screwing around with looking into ways to OC my gpu a tiny bit...i BSOD...so im now sitting at 1.300v and running a blend test along with having WOW open and running and having the same stuff i had running when it blue screened me...im sorta disappointed that this 4.5ghz went from 3+ hours stable at 1.285 to almost 15 hours stable at 1.29v maybe 1.3v is my lucky number
btw am i seriously hurting anything by running a blend test along with playing WOW and surfing the net?