Prime95 failed after 6 hours of blend test! 1.4V Vcore (fixed)/LLC3

In the previous post I was talking about how my CPU overclock has become unstable and that I was trying everything to make it stable again. After many runs of stress tests using Prime95, I settled for 1.4V Vcore in UEFI and started stress testing. No thanks to the huge VDroop this motherboard has, I had to set such a high Vcore. But in reality, the CPU was only getting 1.336V. This is with LLC level 3. 

So I let Prime95 run overnight and went to sleep. Unfortunately after about 6hrs of stress testing, it had crashed with a BSOD with code 0x124. It requires more volts it seems. I wonder how I could get by with just 1.320~1.328V the last time. It definitely must have been the lack of AVX.

So I raised the Vcore to 1.405V in UEFI and came to work, letting Prime95 run while I was at work. It's been about 4hrs 15min and still it has not crashed. Seems like I will probably be able to make it completely stable in this go or at least the next. But what I don't get is, even at LLC level 3, there is a massive VDroop. Either everyone else is lying or they have very  high tolerance. They don't seem to imply the VDroop is that high with LLC2 and LLC3. I'm not sure if this has always been the case with this board. Without using the fixed Vcore mode, you really cannot see the VDroop. And I've been using the Offset mode all this time. 

I just hope that this will be it. 12hrs of Prime stability is good enough for me. This CPU must be a bad clocker. I mean, I bought this CPU second hand but unopened. Someone must have bought a batch of these CPUs and since the ones he tested weren't good clockers, he has returned the whole batch. I guess that's the only way I could have gotten an unopened but used CPU. 

My 4.5GHz overclock on 2600K has become unstable!

It's been a while since I tested for stability of my CPU's 4.5GHz overclock. I ran the blend test of Prime95 of more than 6hrs back then and I felt that was sufficient. However, PC has been giving random lockups in the past couple of months and I didn't want to accept that the reason for this instability was because my overclock wasn't stable enough. For some reason, it was so hard to find the settings that made my PC stable, and I didn’t want to go through all that again. It could be because I wanted to both overclock and save power at the same time. That's not something that's easy to achieve, obviously. Or it could be because the motherboard is not the best when it comes to overclocking. Or it can even be that this CPU is a bad clocker. Or I could have been doing something wrong in the first place.

Anyways, the reason for the recent instability could be due to many reasons. The first one could be because the last time I checked for stability, I didn't use a version of Prime95 that supported AVX instructions. Then, I did a couple of UEFI updates and maybe I needed to change “some values” to make the CPU stable under the firmware that I'm using currently. Or it could well be a problem with the power supply or motherboard or memory.