i7 8700k overclocking help needed

[Hopelez]

Hey,

 

I currently have my new i7 8700k overclocked to 4.5GHz @1.29V, doesn't the voltage sound quite high for this clock?

 

Anyways, when dropping voltage to 1.28V, threads 7 and 8 get errors in Prime95 Small FFT, same happens when going to 4.6GHz regardless of what voltage I set, and at 4.8GHz threads 3 and 4 also start failing. Is this one core just that much worse than the others? Am I just unlucky and received a badly overclocking CPU or is there maybe something else that could be causing this?

 

I ran 10 hours of Prime95 Blend with 4.5GHz @1.29V without any errors.

 

The specs of the new PC:

 

• MSI Z370 Gaming M5
• Intel i7 8700k
• Cryorig H7 cooler with 2 fans
• MSI GTX 1080Ti
• 4x8Gb Kingston HyperX Fury @2400MHz

 

[DarkSmith2]

25 minutes ago, Hopelez said:

The specs of the new PC:

 

• MSI Z370 Gaming M5
• Intel i7 8700k
• MSI GTX 1080Ti
• 4x8Gb Kingston HyperX Fury @2400MHz

Cooler? Its the most important part. Temperatures determine voltage requirements.

[xg32]

either u got very unlucky with ur cpu or ur motherboard's the problem, also what are the temps

[Hopelez]

My cooler is the Cryorig H7, I realize that it is not one of the very best coolers but certainly one of the best ones of the smaller air coolers. Temps seem fine to me, getting to high 80's (celsius) when doing Prime95. Temps are 35-50 when browsing the internet or watching stream or something like that, 60-70 when gaming.

[xg32]

1 minute ago, Hopelez said:

My cooler is the Cryorig H7, I realize that it is not one of the very best coolers but certainly one of the best ones of the smaller air coolers. Temps seem fine to me, getting to high 80's (celsius) when doing Prime95. Temps are 35-50 when browsing the internet or watching stream or something like that, 60-70 when gaming.

try 4.7@ 1.3v and with an avx offset of -2, temps are fine so i'm thinking it's just silicon lottery, also make sure there's a airflow on the vrm

[Hopelez]

Ok I tried your settings and got no errors in 8 minutes of Prime95 Small FFT (I usually get errors way before 8 mins). Thread 1 was however not doing anything, and also shows only 85% max utilization in HWMonitor. The clock also got throttled to 4.5GHz during the stress test. Temps were hitting 100 celsius on some of the cores too... So maybe it is a heat issue after all. I started wondering about my thermal paste application, I remember there being some quirks when installing the cooler, so might have fucked the paste. Maybe I should just try to reapply the paste and see what happens...

 

Uploaded an image from after the test if that would give some extra info.

[Hopelez]

After some reading I really doubt it is the thermal paste either... probably just the cooler is not good enough to overclock this CPU. I'll probably end up buying some AIO water cooling thingy in a month or so to replace this one, for now I'll stay with the factory 4.7GHz single, 4.4GHz all cores boost.

[xg32]

it's the heatsink, u should try optimizing the voltage, the absolute max i'd run on a h7 is 1.25v, ur running 1.315. Whatever your cpu will run on 1.25v is the max oc, keep in mind nothing you do realistically will be as stressful as p95, but u still don't want 90+C even during prime.

[DarkSmith2]

5 hours ago, Hopelez said:

My cooler is the Cryorig H7, I realize that it is not one of the very best coolers but certainly one of the best ones of the smaller air coolers. Temps seem fine to me, getting to high 80's (celsius) when doing Prime95. Temps are 35-50 when browsing the internet or watching stream or something like that, 60-70 when gaming.

Well, the more cooling power your cooler has the more clock you get with lower voltage. You safe 4% power every 10°C.

The H7 is rated with a TDP of 140w. Alot of the bigger Twin Tower coolers are rate for a TDP of ~240w.

[Hopelez]

I'm now running it at 4.4GHz @1.23V and it seems stable. Temps stay under 85 even after a couple hours of prime95. Guess it's time to get a better cooler then. Any recommendations? My case is the Fractal Design Meshify C, it can't fit many of the bulkier twin tower air heatsinks, so I was thinking about some AIO water cooling solution that I should be able to mount to the front.

[xg32]

2 hours ago, Hopelez said:

I'm now running it at 4.4GHz @1.23V and it seems stable. Temps stay under 85 even after a couple hours of prime95. Guess it's time to get a better cooler then. Any recommendations? My case is the Fractal Design Meshify C, it can't fit many of the bulkier twin tower air heatsinks, so I was thinking about some AIO water cooling solution that I should be able to mount to the front.

noctua u12 minimum, i recommend d15 if u dont mind ugly, it performs even better than the AIOs, but if u want AIO, just get a big one, i recommend h100i or 115i ,most overestimate how well they do, but they are more quiet depends on how u set it up. just need a case fan/airflow on the vrm (vrm cooling usually isn't a problem for aircoolers)

[DarkSmith2]

2 hours ago, Hopelez said:

I'm now running it at 4.4GHz @1.23V and it seems stable. Temps stay under 85 even after a couple hours of prime95. Guess it's time to get a better cooler then. Any recommendations? My case is the Fractal Design Meshify C, it can't fit many of the bulkier twin tower air heatsinks, so I was thinking about some AIO water cooling solution that I should be able to mount to the front.

that case will be fine. a 360mm rad fits in the front. I would say

 

Corsair H150i Pro (little bit expansive)

or 

Alphacool Eisbaer 360

 

[Shzzit]

8700k does 4.7ghz all core with default voltage settings.  Turn MCE on.

 

And pretty much anything can cool an 8700k with 1.4v if you are delidded.   

Better cooler wont fix your problem. 

 

1.4v 5.3ghz AVX using an h100i that's years old getting avg temps in stress testing like Large data set OCCT of 54C.  

 

 

The gap between the IHS and cpu is to large from the glue they use on the IHS.  No gap to the smallest gap with liquid metal is key for 20-30C drop in temps. 

[Langley_Man]

Delid time I would say!..

 

Built a few i7 8700k systems and yours seems to be a prime candidate for it my friend. 

 

I would suspect that would take care of your issues.

 

I'm running a simple nzxt x42 v2 at 5g overclock max temps are 72ish