Help with i5-8600k Overclock?

[DeDefiance]

So I've been asking around a few places to try and get some help with my i5-8600k overclock, and it feels like this CPU is the most temperamental thing in the world. I'm pretty new to OC so hopefully this isn't a really stupid error on my part.

The main problem I'm having is that I get constant bluescreens and freezes, and sometimes it just won't even boot into Windows with certain settings. People with exactly the same board and CPU as me are able to achieve 5Ghz with 1.4v, but I'm not even able to achieve 4.8Ghz with that.

These are my system specifications to give an idea of my system;

• i5-8600k
• ASRock z370 Extreme4
• Corsair Dominator DDR4 8GB (x2)
• Corsair RM 550x
• GTX 1070
• Corsair H60 AIO

These are the settings I'm currently using (And they are incredibly unstable. Basically they crash as soon as Prime95 starts. If I up it to 1.4 it makes no difference), however I've tried about every combination under the sun and basically anything other than stock is unstable.

https://imgur.com/a/aCpGbxo

Hopefully someone can provide some insight.

 

[Johan45]

A couple things of note here, first NOT ALL CPUS ARE CREATED EQUAL you can't base your OC on otherseven with the same HW. Second the H60 isn't a great cooler, not that it's bad it's just average. The 8 series CPUs at 1.4 V are very hot, add to that they use a paste based TIM, which, when the voltage gets higher has a hard time transferring the heat. I have an 8700K and it tops out at 1.35V for heat on P95 at 4.8 GHz with a better cooler just to give you an idea. Prime 95 uses AVX instructions which really work a CPU in turn causing a lot of heat. So you have two options, set an all core OC for use with all instructions or use the AVX offset option in BIOS to drop the core speed when the CPU encounters AVX.
What I would do is start at 1.3 V and 46-47 multiplier and test with P95 see what happens. Then adjust voltage/multi as necessary depending on temps.

 

[DeDefiance]

A couple things of note here, first NOT ALL CPUS ARE CREATED EQUAL you can't base your OC on otherseven with the same HW. Second the H60 isn't a great cooler, not that it's bad it's just average. The 8 series CPUs at 1.4 V are very hot, add to that they use a paste based TIM, which, when the voltage gets higher has a hard time transferring the heat. I have an 8700K and it tops out at 1.35V for heat on P95 at 4.8 GHz with a better cooler just to give you an idea. Prime 95 uses AVX instructions which really work a CPU in turn causing a lot of heat. So you have two options, set an all core OC for use with all instructions or use the AVX offset option in BIOS to drop the core speed when the CPU encounters AVX.
What I would do is start at 1.3 V and 46-47 multiplier and test with P95 see what happens. Then adjust voltage/multi as necessary depending on temps.

Thanks. I managed to get 4.8Ghz at 1.35 but my temps are around 100C after 5 minutes of Small FFTs Prime95.
Is this maybe a bit too high and should I lower down to 4.7 so I can lower my V as well to get less temps?

 

[Johan45]

Try testing with blend and see how it does. Small FFTs is the worst case scenario and extremely hot

 

[EarthDog]

You really do not want to go over 90C for that CPU and stress testing. 100C it will start to throttle back.

Small FFT as Johan said is worst case and gaming is 20-30C less than that.

 

[trents]

You need to get a better cooler.

 

[DeDefiance]

Try testing with blend and see how it does. Small FFTs is the worst case scenario and extremely hot

Will give this a try first thing tomorrow. Actually managed to get stable on 4.7Ghz 1.35v I think, and I'm getting around 80-90C on Small FFTs.

You really do not want to go over 90C for that CPU and stress testing. 100C it will start to throttle back.

Small FFT as Johan said is worst case and gaming is 20-30C less than that.

I'll take Johan's advice and see if I can get 4.8 - 4.9 stable on blend.

You need to get a better cooler.

Any recommendations? (Definitely not custom loop!)

 

[trents]

As far as recommendations for a better cooler we need more info:

1. What case are you using. What cooler you choose needs to fit in the case.
2. Do you want to go AIO water or good air?
3. What is the limit of what you would be willing to spend on upgrading the cooler?
4. What part of the world do you live in? What is available here in the US may not be available overseas.

 

[Johan45]

The Swiftech H220X3 AIO and the Noctua NH-D15 are both very good coolers. The swiftech may work slightly better but you need room to mount it. Same goes for the Noctua air cooler, it's quite large but it's also half the price of the AIO. You just need to check dimensions and verify things will fit into your case

 

[avalanche83]

Every CPU is different because they are all taken from different parts of the wafer. I would suggest increasing the speed first until it's unstable, then increasing the voltage in that manner.

 

[DeDefiance]

As far as recommendations for a better cooler we need more info:

1. What case are you using. What cooler you choose needs to fit in the case.
2. Do you want to go AIO water or good air?
3. What is the limit of what you would be willing to spend on upgrading the cooler?
4. What part of the world do you live in? What is available here in the US may not be available overseas.

I've got a nzxt s340 elite case.
I'd prefer water but either is fine.
Uh, not sure.
I live in Australia.

The Swiftech H220X3 AIO and the Noctua NH-D15 are both very good coolers. The swiftech may work slightly better but you need room to mount it. Same goes for the Noctua air cooler, it's quite large but it's also half the price of the AIO. You just need to check dimensions and verify things will fit into your case

I'm not even sure I can buy the Swiftech in my country, I can only find US sites.

 

[trents]

Your case will take a 2x140mm fan AIO water cooler: https://www.newegg.com/Product/Product.aspx?Item=9SIA6ZP5M60998

 

[wingman99]

You just lost the silicon lottery. My i5 8600k will do 5.0GHz at 1.296v prime95.