First time overclocking: 8600k on Asus z370 TUF Plus Gaming - a few problems! | PCSPECIALIST

First time overclocking: 8600k on Asus z370 TUF Plus Gaming - a few problems!

Hi all,

I ordered an 8600k OCed by PCS at 4.6GHz and very happy with it. However, I'm trying to OC to 4.7GHz more just to teach myself how to OC than anything else and running into a few problems on my Asus z370 TUF Plus Gaming board. Before OCing I did a 'control' test in Prime95 with the PCS OC settings of 4.6GHz at 1.3v but the voltages reported in HWMonitor were much higher (1.374.) Reading up on this suggested LLC was too high and an Asus guide I read on OCing Kaby Lake suggested setting IA AC/DC LOAD LINE to 0.01. I did this but the voltages were then much lower than 1.3v (1.225v, even under load), resulting in Core #3 failing after about a minute in Prime95.

Due to this I set IA AC/DC LOAD LINE both back to Auto and tried OCing to 4.7GHz anyway, but even inputting 1.325v and with IA AC/DC LL back on Auto, Core #3 fails after only about a minute in Prime95. I'm really loathe to increase voltages further given the massive voltage offset but don't want to admit defeat!

I'm struggling to find a dummies guide for this as all the terminology appears to be different to my bios, even to other z370 Asus bioses, so wondered if anyone had any idea what I was doing wrong? Have I just lost the 'silicon lottery?'

Heya! So it turns out I was being dumb and looking at the 'VID' voltage and not Vcore so ignore the stuff about voltage being too high. Actually appears it's too low under load: even with LLC Level 6 v droops down by 0.025 under load and only overvolts 0.005 v at idle. Could try L7 I guess? I'm using Prime95 with AVX and no offset. I want to see what it can get to stable without an offset first, or would you just not bother aiming for AVX stability? From what I've heard it'll rarely come up especially if I'm just using it for gaming.


Multiverse Poster
You want the OC to be stable above all else. However, if you end up not using an AVX offset, that probably means you're not pushing the CPU as far as it can easily go for non-AVX workloads. i.e. almost everything in gaming.

What is your full spec out of interest?
What offset would you go for? I've seen 1, 2 and even 3 recommended (though 3 seems mostly for very high frequency). Here it is. RAM now upgraded to 16GB. Got it earlier this year when RAM/GFX card prices were insane so the 1060 3GB is very much a stopgap card - probably until Navi 7nm comes out.

Overclocked CPU Overclocked Intel® Core™ i5-8600K Six Core (3.6GHz @ up to 4.6GHz)
OC BIOS FIle Download Overclock BIOS File
Motherboard ASUS® TUF Z370-PLUS GAMING: ATX, LGA1151, USB 3.1, SATA 6GBs - RGB Ready
Memory (RAM) 8GB Corsair VENGEANCE DDR4 2666MHz (2 x 4GB)
Graphics Card 3GB NVIDIA GEFORCE GTX 1060 - DVI, HDMI, 3 x DP
1st Storage Drive 1TB SEAGATE BARRACUDA SATA-III 3.5" HDD, 6GB/s, 7200RPM, 32MB CACHE
1st M.2 SSD Drive 256GB SAMSUNG PM961 M.2, PCIe NVMe (up to 2800MB/R, 1100MB/W)


Multiverse Poster
Yes, let's hope the Navi rumours are true, or at least close to the mark. :)

And the CPU cooler?
If they're not/not close enough I'll happily go 2070, tis a good card! 240mm Masterliquid Lite! Seems to keep everything in at most the 80s with Prime95 running - usually low 60s - even at 1.4v which I'm trying to avoid.