XMP works when my CPU is stock, otherwise doesn't boot.

[Aslaf]

Hi! I have a G.Skill Ripjaws V DDR4, 2x4GB, 3200MHz, CL16 RAM sticks, i5 6600k and ga-z107-d3h MOBO.

When CPU is stock, I can XMP the hell out of my RAM, but when my CPU is oc'ed, I have to lower Mhz in XMP mode to 2800 to work properly. Moreover, I CAN do it in reversed order, eg: I FIRS set an XMP profile THAN oc my CPU. But I have to add more voltage to it than when I overclock with ram set to 2800 in XMP mode (Or GXMP from "Gimped Xtreme Memory Profile")

What to do My dear PC friends?

 

[Chugalug_]

Are you upping the voltage on the CPU when you overclock?
Sounds like it just isn't booting because your OC settings aren't correct rather than your RAM being the problem.

 

[Aslaf]

Are you upping the voltage on the CPU when you overclock?
Sounds like it just isn't booting because your OC settings aren't correct rather than your RAM being the problem.

Yes, Of course. CPU passed a 6h prime 95 run and 3h OCCT, so OC is rock solid. Just when I set XMP boom, boot failure and have to lower RAM speed to 2800. As I mentioned above, i can easily run stock cpu @ XMP profile set to glorious 3200 Mhz as advertised.

 

[Chugalug_]

Add a bit of extra voltage, it may be that your CPU is hitting bare min voltage requirements and your RAM being overclocked pushes it over that threshhold.
Just in order to remove this as a potential factor, up your voltage by 0.1 and test. 😛

 

[Aslaf]

Add a bit of extra voltage, it may be that your CPU is hitting bare min voltage requirements and your RAM being overclocked pushes it over that threshhold.
Just in order to remove this as a potential factor, up your voltage by 0.1 and test. 😛

Ok, something weird happend. I Couldn't boot with XMP on EVEN when cpu was on stock... I tried to manually set stock settings and do it by using "Load optimized defaults" built-in-bios function. Nothing. Computer booted only when RAM frequention didn't exceed 2800 mhz, BUT than i tried to reset CMOS by putting of a battery and than, tadan, I have a XMP memory and CPU @ 4.5 . I don't understand why and i have to make some stability test. Can anyone explain me what happens? Is my MOBO faulty or something?

Oh, and no, changing CPU voltage offset from 0.080 to 0.090 didnt help back then.

 

[amtseung]

XMP can wreak havoc with your BIOS in ways unforeseen, including an unannounced bump of the BCLK, ring ratio, or even LLC in some rare cases. If you had previously changed settings that the XMP profile wanted to change, you'd have a conflict and things would fail to boot. Clearing CMOS would have reset everything, including clearing those obscure conflicts, allowing the system to work as intended again.

 

[Chugalug_]

Yep.
Also @OP you'll want to set LLC (load line calibration) to high in order to prevent Voltage droop.
Its likely that you accidentally changed something in regards to memory frequency or voltage delivery and that caused instability in the system, not to worry if you've solved it now though!
Enjoy.