I don't think these tests were representative; I think the chip is bad.
Below is the original article. I'll have to do a new one after I get the replacement chip.
I could not get the processor to pass an OCCT Linpack test at 2.9 Ghz. The problem is that the processor heats up quickly to over 72.7 C which is the chip limit. But, when you reduce voltage, the procesor becomes unstable. At 2.9 Ghz the processor gets errors with 1.16 volts. So I tried increasing to 1.18 volts VCORE and cutting the clock down to 2.8 Ghz. The processor is stable at 2.8 Ghz but heats to 75 C. Frankly, I could not get the processor to stay within range higher than 2.66 Ghz with Turbo turned off. I did some screen captures to show this.
The voltage indicated by OCCT on the following images will be slightly less since it drops during testing. When idle, the voltage shows correctly as 1.18 volts.
We now have our baseline. With the stock cooler, the i5-750 cannot be considered to be overclockable or even within limits with Turbo enabled. This means that the vast majority of people who buy systems with this processor have a marginal configuration at best. Intel pulled the same stunt with its original Kentsfield quads which were also out of range at stock speeds. Anand Lal Shimpi was well aware of this but in true overclocker fashion he simply averted his eyes and pretended it didn't exist. I had hoped the problem had been fixed with the G0 stepping and the lower voltage 45nm Penryns but now we have Nehalem and the problem is back.
There may be some Intel fanatics who will think I'm being unfair to Intel but I tested my X3 720 and PII 965 the same way. The X3 720 is fine with the stock cooler while the PII 965 needs improvement. However, it should be noted that the PII 965 in stock configuration is more than adequate and could even tolerate a mild overclock of maybe 100 or 200 Mhz. So, in stock configuration AMD does what it is supposed to while Intel fails. The next step is to bolt on the heftier Freezer 7 Pro cooler and see what happens.