So, I put together a new system (specs below)... Ran it through prime 95, etc, everything checked out a-ok pre-overclocking.
CPU temperature during tests remained very cool (high 20's / low 30's C).

Problem I am having now is that one of the cores on my CPU starts to experience problems when I overclock - that is, prime95 cannot complete stress runs. At 3.1 GHZ core 0 reports a failure due to a rounding problem.
At 3.3 Ghz, core 0 will encounter 100 illegal sumout type warnings before completing even 1 test cycle.
All this time, temps never get high, and I can crank thie cpu up over 3.5 without seeing a core1 failure.

I ran SANDRA, everest, etc at 3.3 Ghz with no failures, and the temperature never got above 35C...

I drop back down to the stock 2.6ghz / and box voltage setting and I can run prime95 as long as I want and never see an issue.

Anyway, I'm just complaining I think - I've got a weak core 0, works fine at the listed frequency, not much I can do about it right? I guess I could try an RMA (newegg) but I'm thinking I don't have a valid reason for a return given it works fine at normal speed

By the way, I used the Tom's hardware guide as a reference, helped a lot, thanks




Specs:

CPU: AMD 5000+ Black Edition
MB: ASUS M3A-H/HDMI AM2+/AM2 AMD 780G HDMI ATX AMD
Graphics: XFX PVT88PYSF4 GeForce 8800 GT 512MB 256-bit GDDR3 PCI Express 2.0 x16
Memory: G.SKILL 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400)
PSU: PC Power & Cooling S61EPS 610W Continuous @ 40°C EPS12V Power Supply
HD: Seagate Barracuda 7200.11 ST3500320AS 500GB 7200 RPM SATA
Case: COOLER MASTER RC-690-KKN1-GP Black SECC/ ABS ATX Mid Tower Computer Case

Cooling: ZALMAN CNPS 9500 AM2 2 Ball CPU Cooling Fan/Heatsink