[SOLVED] Need help overclocking 7700k so i don't blow up my PC

theinfamoustoast

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specs:
MOBO: Asrock Z270 PRO4 - driver up to date
CPU: i7 7700k all cores 4.4ghz
Cooler: Be quiet! Dark Rock Pro 4
GPU: GTX 1060 OC
RAM: Kingston Hyperx fury 2x8 2133mhz
PSU: Corsair 550w

Long version:
I need some assistance from you folks about my overclocking. i got this CPU i would say a year and a half ago and I always intended to overclock but i never really needed it until now. In the past I tried to overclock but my PC stopped booting and with hours of troubleshooting it finally booted and after that i stopped messing with the bios for a while. However I've been looking at a lot more threads and videos to help me with overclocking but i still don't have a definitive answer on how to overclock. I don't really want to exactly copy what someone said in a thread and or video as every motherboard and CPU acts differently. with everything at default my voltage seemed to jump between 1.3v and 1.35v on H/W monitor when stressing the system without any overclocking. This seemed to be really high especially at stock so i updated the bios and set the CPU voltage at a fixed-mode at 1.27v with XMP off. I then wanted to boost the cores a bit so I set CPU ration to all core at 4.4ghz. I also set the LLC to level 2. I want to try and get this higher once i know what i'm doing.

My LLC goes from level 1 which as at the top down to level 4. I know LLC helps to lower or raise voltage when needed but I don't know what the levels mean for example i don't know what a stable voltage should look like. when i set voltage to 1.27v my LLC seems to keep my voltage between 1.245 and 1.255v when on full load. when i'm just on windows however my voltage seems to spike to 1.29v for a bit.

furthermore when i decreased my voltage from 1.27 down to 1.25 but voltage on H/W monitor seemed to be exactly the same but my temps were lower? that got me thinking that its not actually showing the correct voltage if i'm not mistaken or if its got to do with the LLC. My bios also has a boot performance mode. I set mine to max non-turbo performance with the highest being 'turbo performance' i don't think this matters as I've already set my core ratio to all core but i leave it be. Lastly I don't know what to set mine CPU cache Ratio again this is just left at Auto as i'm not sure what to set it to. sorry if this all seems confusing but i just have a lot of questions


Short version:
stock speeds voltage on bios is at 1.3v and jumps to 1.35v which seems to be high for stock with LLC auto.
set all cores to 4.4ghz fixed mode 1.27v set LLC to level 2 but not sure what to put LLC exactly on. (XMP off)
CPU cache ration is set to auto no idea what to do with that
at 1.27v / LLC 2 my voltage on 100% CPU load is between 1.245 and 1.255. however when im just on windows it sometimes spikes to 1.29v? when nothing is running.
Decreased voltage to 1.25v and H/W monitor detects the same voltage output, even for 1.27v but with lower temps - there is where i think LLC is confusing me
boot performance mode? don't know if its needed as I've already set all cores to 4.4ghz constant.

sorry if this seems confusing but i just have a lot of questions
 
Last edited:
Solution
Load Line Calibration is a power delivery curve. Under light or no load conditions it will provide a little extra voltage to the CPU. The idea is to counteract voltage droop under a heavy load, but the response time has some lag to it, so when your CPU ramps quickly to 4.4Ghz in Windows doing almost nothing, the voltage is applied, but not needed, so it will show as spikes on the sensors.

1.27 is a little low,you have underclocked the CPU a little as it normally boosts to 4.5Ghz. Though not necessarily 4.4 across all cores.

1.35 is somewhat typical for 4.8Ghz.
But you also have to account for Vinput or Vin to the CPU power supply This is usually 1.8 to 2 volts. It will need to be 2.0 volts or more for a decent overclock.

Cache ratio...

Eximo

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Load Line Calibration is a power delivery curve. Under light or no load conditions it will provide a little extra voltage to the CPU. The idea is to counteract voltage droop under a heavy load, but the response time has some lag to it, so when your CPU ramps quickly to 4.4Ghz in Windows doing almost nothing, the voltage is applied, but not needed, so it will show as spikes on the sensors.

1.27 is a little low,you have underclocked the CPU a little as it normally boosts to 4.5Ghz. Though not necessarily 4.4 across all cores.

1.35 is somewhat typical for 4.8Ghz.
But you also have to account for Vinput or Vin to the CPU power supply This is usually 1.8 to 2 volts. It will need to be 2.0 volts or more for a decent overclock.

Cache ratio should stay within a few hundred megahertz of your target clock frequency. So if your target is 4.8Ghz you probably want it at 4.4Ghz.

You might want to invest in some faster memory, that will make a bigger impact on the system performance than clock frequency at this point.

For reference:
i7-7700k 5Ghz 1.416 volts, Cache at 4.5Ghz, Memory running at 3000Mhz effective (memory at 1.25 volts as I recall) (1500Mhz). Watercooled and delidded (re-applied with normal thermal compound not liquid metal). My CPU isn't the best sample and needs a lot of voltage to do 5Ghz, your results may vary.

If you want more examples and a decent guide:
https://www.overclock.net/forum/5-intel-cpus/1621347-kaby-lake-overclocking-guide-statistics.html

And this applies to Skylake, Kabylake, and the two Coffeelakes:
https://www.tweaktown.com/guides/8481/coffee-lake-overclocking-guide/index.html
 
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Solution

theinfamoustoast

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Thanks Eximo for the reply this will be very helpful, i knew my ram would be an issue once i started overclocking but it was at the time where ram sticks were stupidly high in terms of price. I may change the timings and increase it to 2400mhz. Although would this mean that i would have to enable XMP?
 

Eximo

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I have a few games that are certainly more CPU bound (RTS and MMO) than GPU bound. Why I am slightly tempted to pick up an i7-9700k (on sale slightly) and hack it into my Z270 board. Same thread count, but it might just be the last upgrade I do before DDR5 comes out.

If your memory has an XMP profile for 2400Mhz, then it is 2400Mhz memory. Probably doesn't from the sound of it, this would be straight overclocking by setting the memory speeds and timing manually.

Though to be frank, I am not much of a memory overclocker. I pretty much just buy the speed I want at the time. Bonus in that this memory runs at 3000Mhz below its voltage spec, which does say I could over clock it or tighten the timings, but I've not had a huge need.

Overclocking is kind of fun, so is BIOS modding to stick it to Intel. If you bought K and Z, might as well take advantage, you paid for it.