[SOLVED] Why is my I7 8700k processor overheating? Replaced thermal paste several times already. Any help is appreciated. Thanks.

Aug 23, 2020
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Core temps of my i7 8700k will reach 90-100C after a few minutes from start-up. I removed the motherboard from the and tested with PSU, RAM, M.2 only but still with high temp.

Procie: i7 8700K (never overclocked)
PSU: Cougar 1050w
Mobo: Aorus z370 ultra gaming
RAM: 8GB Gskill Tridentz 3000
M.2: Samsung EVO
CPU Cooler: corsair H100i V2 (pump from icue indicates almost 2000rpm with fans visbly spinning. I can also feel that one of the water hoses from the CPU cooler is warmer than the other. )

I dont have any extra psu or cpu cooler to try and replace them for troubleshooting . I have icue and another app indicating that core temps are 90-100C. Windows works fine but i closely monitor the core temps and shut it down after a few minutes when core temps are high.

Any help is appreciated. Thank you.
 
Solution
Yeah it sound like pump failure to me, I'm assuming you put thermal compound on tightened up the in a even x pattern. But years ago on a amd fx 9590 I had a corsair H110 and the pump died on it and it drove me crazy trying to figure out the cause. but if your not attached to water cooling I'd recommend replacing it with a noctua nh-d15 air cooler, no rgb or anything like that but it's a great cooler. I'm running one on a 7960x and max load in prime 95 70 to 80 C.
Aug 23, 2020
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Thanks a lot. I will consider doing substitution of component for troubleshooting starting with the cpu cooler. At this moment I am also trying to read more on this problem then buy a new cooler for testing if nothing works without spending.
 
Core temps for the i7 8700k can occasionally reach high 90C when under high load. TJmax is 100C so it should be OK for short periods however if sustained will degrade the CPU.
Core voltage is probably the issue so go into Bios and check. Try to lower Core voltage in .01V steps down until the system becomes unstable, then bring it back up in .01V steps till stable and stress testing at each change of voltage to check your temps.
Certainly the H100i will cope at base frequency and from your description the fans and pump are functional.
What TIM did you use and how was it applied?
What Case and fans are you using? Do you have good air flow thru the case?
 
Aug 23, 2020
4
0
10
Core temps for the i7 8700k can occasionally reach high 90C when under high load. TJmax is 100C so it should be OK for short periods however if sustained will degrade the CPU.
Core voltage is probably the issue so go into Bios and check. Try to lower Core voltage in .01V steps down until the system becomes unstable, then bring it back up in .01V steps till stable and stress testing at each change of voltage to check your temps.
Certainly the H100i will cope at base frequency and from your description the fans and pump are functional.
What TIM did you use and how was it applied?
What Case and fans are you using? Do you have good air flow thru the case?

Thanks. I will try to play around the bios and see if I can reduce core voltage with 0.01 volts increments. Never done it before and all the settings in bios are currently in auto and default.

I use a deepcool thermal paste and spread i thinly on the processor before mounting the cpu cooler. My motherboard is currently on a cardboard on my desk since I pulled it out from the case and disconnected all non essential components for easy troubleshooting. My case was an old NZXT H440 with 3 corsair AF in front, 1 corsair AF at back and 2 corsar SP for the radiator on top. I have GTX 1070 in SLI and both dont have a problem with their temps before I removed them. Thanks again.
 

Afro_ninja199

Reputable
Aug 10, 2019
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Thanks. I will try to play around the bios and see if I can reduce core voltage with 0.01 volts increments. Never done it before and all the settings in bios are currently in auto and default.

I use a deepcool thermal paste and spread i thinly on the processor before mounting the cpu cooler. My motherboard is currently on a cardboard on my desk since I pulled it out from the case and disconnected all non essential components for easy troubleshooting. My case was an old NZXT H440 with 3 corsair AF in front, 1 corsair AF at back and 2 corsar SP for the radiator on top. I have GTX 1070 in SLI and both dont have a problem with their temps before I removed them. Thanks again.

try replacing the paste and only put a small dot in the middle
 
Deepcool Z5 has a thermal conductivity of 1.46W/m-K . In other words it's crap. Decent paste should be around 8W/m-K.
AS5. MX4 orThermal grizzly are good. and can be as much as a 10C difference in temps.

BTW: I would say your AIO pump is functional as there is a difference in temps from each tube.
 
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Some pump failures indeed resort in one hot tube, the other cold...; no one should truly expect a radiator with a few fans to act as a powered chiller unit as far as pump intake/output hoses...

Pumps often degrade after a few years, with their internal micro-cooling fins clogging with assorted gunk/contaminants, etc...
 

HaizRail007

Distinguished
Mar 21, 2015
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Yeah it sound like pump failure to me, I'm assuming you put thermal compound on tightened up the in a even x pattern. But years ago on a amd fx 9590 I had a corsair H110 and the pump died on it and it drove me crazy trying to figure out the cause. but if your not attached to water cooling I'd recommend replacing it with a noctua nh-d15 air cooler, no rgb or anything like that but it's a great cooler. I'm running one on a 7960x and max load in prime 95 70 to 80 C.
 
Solution
Aug 23, 2020
4
0
10
Thanks for all the help. After reading all your comments, I also suspected that it was the cooler and decided to buy a new one. Installed it with its stock thermal paste and core temps are now near 30.0 C at idle. Thanks gain. RIP H100iV2 :(
 

Phaaze88

Titan
Ambassador
Thanks for all the help. After reading all your comments, I also suspected that it was the cooler and decided to buy a new one. Installed it with its stock thermal paste and core temps are now near 30.0 C at idle. Thanks gain. RIP H100iV2 :(
It's inevitable with liquid coolers - it may even be the greatest downside to them; needing a backup cooler on hand when they do fail, because the user can't really use the PC during that time.
That's one advantage an air cooler does have over them; when it's fan(s) happen to fail, the heatsink can still be kept cool via the chassis fans.
 
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