What is wrong with my CPU (overclocking)

[aubycek]

Since I bought my i5-6600k, I knew my chip wasn't the best at overclocking. It could never handle an 'average' OC, like other people could achieve with this CPU (for example 4.5GHz at 1.3V). The odd thing about this is that unstable overclocks always hard-freeze my whole PC, instead of BSODing. So I just settled for 4GHz 1.2V, which was perfectly fine - ran at these settings for like 2 years without problems.

I've recently decided to overclock it more, but the damn thing can't even handle 4.2GHz at 1.36V, with LLC being either at Standard or High. Temperatures were fine and voltages corresponding to what I set them to. Again, people would reach 4.2GHz at almost stock voltages (1.2V).

What can be the problem here? I can't be THIS unlucky with my chip, there has to be something more to it... My BIOS is up to date, I even reinstalled Windows but the results are the same, so anything software related has nothing to do with it. I've read several guides on overclocking and even tried to OC based on a YouTube video where they had the same MOBO and CPU, so I don't think I'm doing it wrong. To make matters worse, it now started freezing even at my previously fine settings (4GHz 1.2V).

Note: I have replaced my GPU, PSU and all storages, but the same problem still persists, so these parts can't be the problem.

So, to conclude my questions: Why are unstable overclocks hard-freezing my PC, instead of giving me a BSOD, as it usually does to other people? Why could this be happening, or what can I do?
Here are my specs:

• CPU: i5-6600k
• MOBO: Gigabyte Z170 Gaming K3 (rev 1.1)
• RAM: DDR4 HyperX Fury 2x8GB 2133MHz CL14
• GPU: MSI GTX 1060 6GB
• PSU: Seasonic Focus Plus Platinum 650W
• Storage: Samsung 960 Evo

Any help is appreciated.

[Jurrunio]

3 minutes ago, aubycek said:

Why are unstable overclocks hard-freezing my PC, instead of giving me a BSOD, as it usually does to other people?

This is normal, failed CPU OCs in my experience lock up just as often as blue screen. It's when I use unstable memory settings which it blue screens a lot more than locking up

 

5 minutes ago, aubycek said:

Why could this be happening, or what can I do?

Overheating? Lack of loadline calibration?

[aubycek]

5 minutes ago, Jurrunio said:

This is normal, failed CPU OCs in my experience lock up just as often as blue screen. It's when I use unstable memory settings which it blue screens a lot more than locking up

 

Overheating? Lack of loadline calibration?

First of all, thanks for the reply.

As I stated above, my temperatures of the whole system are very decent. CPU temps never exceed 55C under heavy load.

I had LLC set to high, which helped to keep the voltages very close to what I set it to, but that didn't seem to help.

[Jurrunio]

10 minutes ago, aubycek said:

First of all, thanks for the reply.

As I stated above, my temperatures of the whole system are very decent. CPU temps never exceed 55C under heavy load.

I had LLC set to high, which helped to keep the voltages very close to what I set it to, but that didn't seem to help.

You overclock without touching BCLK (default 100MHz) right?

[aubycek]

Just now, Jurrunio said:

You overclock without touching BCLK (default 100MHz) right?

Not BLCK, CPU clock ratio (as every guide suggests)

[Jurrunio]

12 minutes ago, aubycek said:

Not BLCK, CPU clock ratio (as every guide suggests)

Then you have to try a different board. Preferably not a low end one.

[aubycek]

1 minute ago, Jurrunio said:

Then you have to try a different board. Preferably not a low end one.

I think I will just leave everything at default speeds and upgrade everything in a few years. Thanks for helping me though.