HELP 2nd 8700K voltages,temps & clocks drop simultaneously after 10 secs

[Apparent]

Hello can anyone please help me!

specs
8700k
maximus x hero
evga supernova 750 g2
h100i v2
domintor platinum 16 gb 3200 cas 16
crystal 570x case
ssd evo 850 250 gb

creating 3rd thread but found answers so far for the most part clearly heading in wrong direction

FIRSTLY my settings are at 'stock' with MCE disabled
as of this date still no overclock till i resolve this issue.

So, this is my SECOND 8700k, the issue is simple,-i bought the first as soon as the first batch was available in the UK and since then with both CPU's had the same issue as follows ;

it started with me having to lower my VCCIO & VCCIA when enabling XMP otherwise the bios would set high voltages when enabling it causing the system to POST twice with code 00 showing for the quick second before shut off

while wondering why it would cause it to switch off pc immediately after powering on and then starting up fine i decided to stress the cpu.

Now when i run AIDA 64 or prime 95 the temps voltages & clock speeds would simultaneously drop after appx 5-10 secs from around 75c to around 55-60c on my h100i v2 AIO cooler. Note:
AIDA or prime does not detect any throttling of cpu!

I was instructed here to RMA cpu which was tested and replacement was given, reason being "overheating & BSOD"

whether it was truly doing this i can't be sure ( they could just be lazy and give me a new one) anyway i received the second ,sealed & tested, -same exact issue.

core voltage depending on settings can up to 1.328v from appx 1.1 v. before theu drop.

the drop is nor to the lowest clock or voltage but just a few hundred mhz. So from 4.3 ghz it drops to around between 3.9 to 4.1 ghz.

i have 2 PSU's tested 2 gpu tested and 3 coolers tested.
Interestingly the 3rd cooler ( 4770k stock cooler) i tested and found that the clocks,voltages and temps would not go down and rather the cpu WOULD throttle due to this and so from that perspective seems fine
but because it is not a sufficient cooler i would ofc assume ,
temps were reaching 90+ and everything would only downclock & throttle when it exceeded this. while i quickly stop test.

applied all 3 bios
current 1103
windows 10 FCU

Any suggestions..?

vrm's/ mosfets overheating ..??

motherboard faulty, no seal was on the motherboard imo.

 

[Calvin7]

CPU
Low power features
◾ Core C1/C1E, C3, C6, C7 and C8 states
◾ Package C2, C3, C6, C7 and C8 states
◾ Enhanced SpeedStep technology

You can change power scheme in Windows. Windows performance/power saving mode is set to "full performance" should fix the issue.

Using memory that is for overclocking but not overclocking may cause the PC to reboot to train BIOS memory settings.

I don't follow you on all the CPU cooler changes. You may not know how to apply thermal compound correctly.

As for the "no seal was on the motherboard imo. concern", it sounds like you are a novice with little experience purchasing motherboards. You should not expect such packaging as that sort of thing does not occur.

 

[Apparent]

CPU
Low power features
◾ Core C1/C1E, C3, C6, C7 and C8 states
◾ Package C2, C3, C6, C7 and C8 states
◾ Enhanced SpeedStep technology

You can change power scheme in Windows. Windows performance/power saving mode is set to "full performance" should fix the issue.

Using memory that is for overclocking but not overclocking may cause the PC to reboot to train BIOS memory settings.

I don't follow you on all the CPU cooler changes. You may not know how to apply thermal compound correctly.

As for the "no seal was on the motherboard imo. concern", it sounds like you are a novice with little experience purchasing motherboards. You should not expect such packaging as that sort of thing does not occur.

thermal compound is fine
i prefer pea sized amount
and always use this method in my other build
i have.

the power settings are left as default in bios as is everything else apart from high performance in windows loading xmp,
mce off and lowering the two mentioned voltages since they were two high.

regarding the motherboard purchase yes it was very bad idea to even bother
but i was tempted to test after seeing that everything 'looked' untampered with. The box didn't seem to even have a seal mark left over.
however after time had passed by i just continued to test around.

with the cpu coolers i have 2 AIO coolers, when i use them
the issue occurs where the temps, clocks voltages decline after 5-10 secs when stress testing but when using an intel stock cooler they do not until it actually throttles due to temps hope that clarify's the issue.
im realbench the temps, clocks, voltages appear fine avg temp 65-67c clock speeds between run between 4199 to 4300mhz vcore between 1.2- 1.28


i should also mention at idle clock speeds seem to jump at times from 800 to anywhere up to 4600mhz on 4 or 5 of the cores, obviously the jumping doesn't concern me but it is the clocks where maybe 5 of the cores are clocking higher than the spec i thought they should be, just a little curious as to why that is.