Newbie 8700k 4.8 oc, anything need changing please?

Potty27 · 29 Apr 2018 at 20:57

Hi all,

Not really done much oc'ing, certainly not on more recent CPU's anyway.

I've just got a 8700k, ASRock z370 extreme4, 16gb 3200 8 pack ram, d15 cooler (only using the middle fan currently) and no gpu as my 1060 gpu is still on my old pc.

After some playing with the settings I am at 4.8 (target speed) with the following changes:

v-core: 1.29
llc: level 2
Short and Long load set at 170w max
AVX negative offset: 3

Tested using some benchmarks, but mainly from running Prime95 (version 26.6 as the more recent versions seem to get crazy hot due to the AVX I believe?) blend for 2h.

Here is a screenshot during the Prime95 after 2 hours:

Anything I have missed or should change please?

Many thanks.

Potty27 · 29 Apr 2018 at 20:58

P.s. Have not delidded the CPU and have no plans to(too scared!

).

Matt26LFC · 29 Apr 2018 at 21:12

Looks fine to me, use your system like you would each day, play some games, surf the web, photo edit, whatever it is you do, if not BSODs or other weirdness call it a day and enjoy your rig!

Potty27 · 29 Apr 2018 at 23:21

Cheers Matt

Potty27 · 30 Apr 2018 at 05:17

Oh one thing I was unsure about was the LLC setting and vdroop, as idle I have 1.29 v core, but under 100% load this drops to usually 1.212. If I lowered the LLC setting, could I run stable at a lower fixed vcore?

Kirby Wurm · 30 Apr 2018 at 21:55

Seems a good result. I just bought the same CPU/mobo combo although I opted for 3200MHz CL16 Team Group memory. On air I've managed to get 4.8GHz at 1.25v (no delid) with and LLC of 1 and 42 on the uncore. I tried dropping the LLC but couldn't get it stable when working down from 1.3 but may give it another go now I know 1.25v is 24/7 stable.

I've just bought a Corsair H115i to help tame it as my Thermaltright Archon SB-E X2 got pretty noisy at load (still keeping Prime95 down to 79c though) and I want to give 5GHz a shot. It performs nearly as well as the Archon at the lowest setting so that bodes well.

Potty27 · 1 May 2018 at 14:55

Kirby Wurm said:
Seems a good result. I just bought the same CPU/mobo combo although I opted for 3200MHz CL16 Team Group memory. On air I've managed to get 4.8GHz at 1.25v (no delid) with and LLC of 1 and 42 on the uncore. I tried dropping the LLC but couldn't get it stable when working down from 1.3 but may give it another go now I know 1.25v is 24/7 stable.

Tried using llc1 and need 1.25 to be stable, we have a draw it seems

77-78 max temp for prime95. Thinking to leave it at this.

Just had a go oc'ing the ram a bit, appears to be stable running 3333 CL14 at 1.4v (xmp with clock set at 3333 and raised voltage to 1.4 as people recommend).

Seems timings are quite important for coffee lake, so wondering if I should try 3466 keeping timings as they are? Or just settle with what I have.

Kirby Wurm · 1 May 2018 at 18:18

Potty27 said:
Tried using llc1 and need 1.25 to be stable, we have a draw it seems 77-78 max temp for prime95. Thinking to leave it at this.

Just had a go oc'ing the ram a bit, appears to be stable running 3333 CL14 at 1.4v (xmp with clock set at 3333 and raised voltage to 1.4 as people recommend).

Seems timings are quite important for coffee lake, so wondering if I should try 3466 keeping timings as they are? Or just settle with what I have.

You win! Seems 1.25v wasn't quite stable so I've settled on 1.27v. I've actually decided to get it delided for £15 plus postage (cheaper than buying the kit for something I may only do once) as my H115i can get quite loud at times and I wouldn't mind shooting for 5GHz just for the hell of it.

As for the memory this is a good article and would indicate 3333 CL14 is plenty fast enough: https://www.techpowerup.com/reviews/Intel/Core_i7_8700K_Coffee_Lake_Memory_Performance_Benchmark_Analysis/.html

Potty27 · 2 May 2018 at 04:24

Kirby Wurm said:
You win! Seems 1.25v wasn't quite stable so I've settled on 1.27v. I've actually decided to get it delided for £15 plus postage (cheaper than buying the kit for something I may only do once) as my H115i can get quite loud at times and I wouldn't mind shooting for 5GHz just for the hell of it.

Let me know how you get on with the delid

think I could probably get to 4.9 stable on air, but max temps would likely be in the mid-high 80's. Think 5 would be possible with a delid, but to scared to do it currently atleast!

Kirby Wurm said:
As for the memory this is a good article and would indicate 3333 CL14 is plenty fast enough: https://www.techpowerup.com/reviews/Intel/Core_i7_8700K_Coffee_Lake_Memory_Performance_Benchmark_Analysis/.html

Cheers, looks like I'll just leave it at this

Kirby Wurm · 4 May 2018 at 13:07

Potty27 said:
Let me know how you get on with the delid

Well it's back and first results are very impressive. Idle temps are under 30°c, load temps in Prime95 are now 72°c, a 16 degree reduction, and all this with my H115i's fans topping out at 1500rpm, noticeably quieter than before! I've dropped vcore to 1.25 and it now seems stable. Going to shoot for 5GHz later. Very pleased!

Potty27 · 4 May 2018 at 13:13

Kirby Wurm said:
Well it's back and first results are very impressive. Idle temps are under 30°c, load temps in Prime95 are now 72°c, a 16 degree redureduc, and all this with my H115i's fans topping out at 1500rpm, noticeably quieter than before! I've dropped vcore to 1.25 and it now seems stable. Going to shoot for 5GHz later. Very pleased!

Nice!

Could I ask who you used to do it please?

Kirby Wurm · 4 May 2018 at 17:16

Potty27 said:
Nice!

Could I ask who you used to do it please?

Yeah, it's one of two offering the service via Fleabay. I used the one based in Ashford as he uses nail varnish to coat the capacitors for added protection from overflow. His communication was fantastic and turnaround time was very quick, sent it Wednesday morning and received it back around 10am today. For £15 (plus £12 for special delivery each way) I think it was well worth it.

Potty27 · 4 May 2018 at 18:36

Kirby Wurm said:
Yeah, it's one of two offering the service via Fleabay. I used the one based in Ashford as he uses nail varnish to coat the capacitors for added protection from overflow. His communication was fantastic and turnaround time was very quick, sent it Wednesday morning and received it back around 10am today. For £15 (plus £12 for special delivery each way) I think it was well worth it.

I see thanks!

I've heard another person talking highly of the chap from Ashford.... so I am quite tempted!