Intel "Coffee Lake" Builders Thread

Discussion in 'CPUs and Overclocking' started by Crono, Sep 26, 2017.

  1. Dale Chalfont

    Dale Chalfont Junior Member

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    I saw someone a few pages back comment that they were ram speed limited on z370.

    I am putting a pc together with a z370 gaming 5, 8700k and corsair rgb 4x8 3600mhz ram.

    I was hoping for 4.7ghz at 1.25 and to overclock the ram to 3866mhz at default voltage assuming it was a given as I saw a review of the lower clocked 3466mhz ram kit which was also b die like mine reaching 3866 at the timings my ram has at xmp.

    Also on overclockers I saw speculation that 3866mhz/4000mhz would be the max ram speed for 4 modules used with an overclocked 8700k becauae of stress on the board.

    Is 4.7 at 1.25 a reasonable expectation with a noctua d15 with no avx offset for gaming and does anyone have any experience of being ram speed limited with 4 modules?

    Thanks
     
  2. IndyColtsFan

    IndyColtsFan Lifer

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    I can't comment on the RAM - I'm using two sticks of DDR-4 3200 CL14 RAM currently and was going to wait until RAM prices drop to add another 2 sticks, but maybe Santa Wife will bring them to me instead. :)

    Anyway, regarding OC, I didn't see you mentioning if your chip is delidded or not. Heat may be your biggest issue and delidding can take 10-15 degrees off of your temperatures. Regarding your voltage, you might be able to achieve your goal if you set LLC to level 2 (try that first) or level 1. If that doesn't work, you'll need to up the voltage. For me personally, I don't want to consistently run at 1.4 v or over. In my case, I have the BIOS set to 1.375 volts with LLC at level 2, AVX offset set to -2, and chip and cache multipliers at 50. If I run the Prime small FFT test, CPU-Z shows Vcore drops to the 1.25 to 1.26 range and my temps average around the 70 mark for the entire CPU (3 cores stay in the upper 60s, 3 cores go into the lower 70s). Note that 1) My CPU is delidded 2) I'm using an Arctic Liquid Freezer 240 with MX-4 paste 3) My CPU was binned by Silicon Lottery at a guaranteed 5.1 Ghz with -2 AVX offset at 1.41 volts. So I do have some headroom, but I don't want to run 1.4 V 24/7.

    Prior to the config above, I had Vcore set to auto with an offset of 100 mV and LLC at the default level 3. At 5 Ghz and with no load, Vcore was varying between 1.32 and 1.41 and was at 1.41 a little too much for my comfort zone. That's when I implemented the settings in the previous paragraph and not only have they reduced the voltage and been stable, they also dropped my temps 4-7 degrees.
     
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  3. Dale Chalfont

    Dale Chalfont Junior Member

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    Thanks for the response.

    Yeah, no plans to delid. Was going to set it to 1.2 at 4.6 with the lowest level of llc turned on....gigabyte apparently uses 'performance', 'high' and 'turbo' etc rather than level 1, 2, 3 descriptors, and xmp for ram which is 3600 and then if that passes aida64 I was going to try for 1.25 for 4.7 and 1.275 max for 4.8. And I am planning to set cache to maybe x44 or x45.

    Noctua d15 cooler though and kryonaut thermal paste, I'm not even going to try for 4.9, 5, or anything over though.

    Once I get a stable o.c I will boost ram ti 3866 or 4000mhz, but was trying to figure out what level of overclocking restricts memory clocks.

    Eg. If i can set the overclock to 1.2volts 4.6ghz with x44 cache, lowest llc and set ram to 4000mhz cl18 at 1.35 ( default ) to 1.4 volts then that would save me a massive headache of fussing over the last few hundred mhz, especially if I am going to be ram speed limited to 3600mhz if I try for 4.7-4.8.

    From what I have read 4133, 4266 is easy with 2 sticks on these boards but 4 dimms is too much strain with an o.c.

    Guess I'll find out in a few days when my orher parts arrive.

    I hope Santa Wife is kind to you. Mind slung me $1000 to finish this build...now I'm in deep with the Wifey Creditor. Hopefully she won't break my legs.
     
    #1603 Dale Chalfont, Dec 3, 2017
    Last edited: Dec 3, 2017
  4. IndyColtsFan

    IndyColtsFan Lifer

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    I think you'll probably be fine. You've got a good cooler and paste, so I think you'll just need to tweak it until you can find that voltage sweet spot.
     
  5. Dale Chalfont

    Dale Chalfont Junior Member

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    Awesome thanks. All the avx offset and prime 95 cpu destruction stuff has me paranoid.
     
  6. IndyColtsFan

    IndyColtsFan Lifer

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    Just remember - Prime95 is an EXTREME case. You will likely NEVER have that sort of load on your CPU in real-world scenarios. You can even have cases where your system will crash on Prime95 but be perfectly stable and usable in everything else.
     
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  7. TahoeDust

    TahoeDust Senior member

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    Looks like we are more or less in the margin of error. I did see s light bump going from 4.8GHz to 5.0GHz, so we must not be totally GPU limited.

    7820x - 4.8GHz
    Stock clock/mem 1080 ti FTW3
    [​IMG]

    7820x - 5.0GHz
    Stock clock/mem 1080 ti FTW3
    [​IMG]

    Let's find some more stuff to run!

    Edit: The benchmark is NOT triggering my AVX offset. I heard there was a platform bug that is causing it to to false trigger on z370. Maybe that is true.
     
    #1607 TahoeDust, Dec 3, 2017
    Last edited: Dec 3, 2017
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  8. IndyColtsFan

    IndyColtsFan Lifer

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    Yeah, my clock definitely dropped to 4.8 GHz when running the benchmark.
     
  9. TahoeDust

    TahoeDust Senior member

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    Interesting. I wonder when/how that will be resolved.
     
  10. RichUK

    RichUK Lifer

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    BF1 is a good real world test. I've had a failed prime OC also fail in BF1, then a stable prime OC not fail in BF1.
     
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  11. StinkyPinky

    StinkyPinky Diamond Member

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    Just curious. When you guys get a cooler do you use the paste it comes with, or remove it and put on your own? Just wondering if that makes a difference.
     
  12. IndyColtsFan

    IndyColtsFan Lifer

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    Depends what paste it comes with - Noctua has very good paste (forget the exact name) as does Arctic with their MX-4. Otherwise, in the past, I would use Arctic Silver rather than the included paste.
     
  13. DrMrLordX

    DrMrLordX Diamond Member

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    I've been on liquid metal TIM since 2009. So for me it's CLU or Conductonaut (recently switched to Conductonaut).
     
  14. IndyColtsFan

    IndyColtsFan Lifer

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    Be advised that if you use a CPU from Silicon Lottery, the use of liquid metal TIM will void the warranty, as it gradually removes the CPU markings on the IHS.
     
  15. Dale Chalfont

    Dale Chalfont Junior Member

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    Any advice on VCCSA and VCCIO settings for memory overclock?

    Overclockers suggests manual 1.15 for both for 3600mhz and 1.2 for both for up to 4000mhz. Does that sound like an over/underestimate?
     
  16. DrMrLordX

    DrMrLordX Diamond Member

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    I haven't bothered with them yet. But I've been voiding warranties on CPUs for awhile now so no skin off my nose.
     
  17. thxdd

    thxdd Member

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    Finally got everything together for my build, I'll hopefully have it up and running this weekend. If there's any interest, I can share some before/after benchmarking over my 3770K@4.5.
     
  18. coercitiv

    coercitiv Platinum Member

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    1.2V is the last "safe" value considered by the Z370M MSI BIOS for VCSSA, which is ironic since the Auto settings will set the voltage far above that when enabling XMP. Go with 1.15V and default XMP settings for your first try, and check for stability. IIRC you can set different values for VCCSA and VCCIO, but keep them within 0.05V of each other.

    Personally I'm at 1.2V for VCSSA and 1.16V for I/O, but only because I'm overclocking my non-B-die RAM from 3200 > 3466 using same timings and did not bother testing stability bellow 1.2V (I think Auto sets it to 1.3V).
     
  19. Dale Chalfont

    Dale Chalfont Junior Member

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    Awesome thanks, yeah I read that auto set it way higher than neccessary which is crazy given how high people have seen it go.

    I'll set it at 1.15 for both for xmp speed at 3600mhz and see how high I can go without increasing it to 1.2 and go to 1.2 as a last resort.
     
  20. PhonakV30

    PhonakV30 Senior member

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    anyone with 8700K at 5.2Ghz , What's your score of CB R15 ? ST / MT , thanks.
     
  21. thxdd

    thxdd Member

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    I just got my system running last night, am at 5.1 currently. I will post my score at 5.2 if I can hit it this afternoon.
     
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  22. Muadib

    Muadib Lifer

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    Just got around to overclocking my 8700k on a Gigabyte's Z370 Aorus Gaming motherboard, and I have a question. The AVX setting on the board are in positive numbers, and yet several of you are using negative figures.
    What's the story? I have my chip at 4.9 now, but would like to hit the mystical 5.0 if I can.
     
  23. DrMrLordX

    DrMrLordX Diamond Member

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    It's pretty normal to run a negative AVX offset. That'll let you hit higher clocks outsiude of AVX workloads. AVX tends to stress each core more than anything else, which is the reason for negative offset.

    Have you tried benching anything that uses AVX2 for example?
     
  24. LTC8K6

    LTC8K6 Lifer

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    Gigabyte defaults to a positive AVX offset? That would be silly.
     
  25. IRobot23

    IRobot23 Senior member

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    People will have hard time believing it.