CPU Hot 8700

Snajo

Case Bender
Original poster
Dec 29, 2019
2
0
NCASE M1 V5
EVGA H370 Stinger, 8700(non-k)
Noctua D9L w/two fans at ~1900rpm (Set as intake from rear)
Ambient 18c (cold ass basement)

CPU-Z Stress Tester (default? didn't notice any settings):
94c Side/Top Panels ON
85c Side/Top Panels REMOVED

OCCT (CPU:eek:CCT default settings):
90c Side/Top Panels ON
80c Side/Top Panels REMOVED (reading fluctuates +/- 4c)

First: Is this normal? If not, why might I be seeing higher temps than reviews?

Second: When the cpu is place under load, fan speed and temperature increases almost immediately to 70 - 80c. This makes me wonder if the die is poorly transferring thermal energy to the heat sink. It likewise drops to sub 50c within three seconds of ending either stress test. Is this temperature change normal for an i7 8700 or indicative of a sub-par thermal transfer between the die and temp-spreader or temp-spreader and heatsink? It's particularly annoying because anytime the cpu is under a significant load for even just a few seconds, fans go to max.

Plans: I have a blower 1080 ti, a strix 1080 ti deshrouded with 120mm fans underneath, and a 1080 ti with a g12 adapter installed. The blower model is obnoxious, the strix setup is decent and I haven't tested the G12 card with aio.

Lastly: Before I buy a different cpu and/or mobo or cooler, is there anything else I should try? I do have a 240mm evga AIO that I can test on the CPU in an open-case config. I suppose I can test that to see if the rapid temp changes are consistent, but I'd like to see what ideas there are here first.

screenshot of HWiNFO

 

neilhart

Cable-Tie Ninja
Apr 18, 2017
148
269
Yes the NH-D9L is a great cpu cooler given a good installation. I have used this cooler on two hacks and documented one here at:

With your 8700 I would check that the cooler is fully contacting the CPU heat spreader by checking the pattern of the thermal compound. Also you may want to de-lid the unit and reinstall with a good thermal compound on the CPU device (see discussion groups on de-lidding).

Good luck with your project.
Neil
 

Snajo

Case Bender
Original poster
Dec 29, 2019
2
0
Nice project you've got there! Looks like it'll be a pretty quiet build. I've never been able to do custom work to the point of having a nice-finish. Everything I build myself ends up looking a bit like a middle school science project - maybe functional, but still pretty 'eh'.

It does look like I'm running hotter than expected. I took the sink off to repaste and the first-mount past was thin in the middle and thicker on the outside. I'd say it's pretty ideal for something non-precision lapped stuff. I'm guessing the die-heatspreaker transfer is where I'm having problems. I have another cooler I can try, but I'll probably delid since that sounds interesting. Thanks!
 

MultiDoc

Airflow Optimizer
Bronze Supporter
Feb 2, 2018
303
197
Definitely delid your cpu and also try to reseat the cooler with good thermal paste. You should see a drop of at least 10-15C

P.S: I use the same cpu and cooler myself but it’s delided and have never seen the temps you’re getting, with an ambient at around 22-23C the max ive seen (while maintaining near silent operation) is 78-80Cin benchmarking, if I use a more reasonable fan curve (but also more audible, which I hate) the temps never go above 75C. In normal operation and even in hours long heavy gaming it sits happy around 70C
 

ignsvn

By Toutatis!
Moderator
Apr 4, 2016
1,283
1,084
Indeed that's hot. Highly likely CPU cooler contact issue.

Make sure the whole thing evenly makes contact with the CPU.
 

tinyitx

Shrink Way Wielder
Jan 25, 2018
1,735
1,586
I think you have more than 1 problem.
1) as you said, either the thermal transfer between the die and the heat spreader or between the heat spreader and the D9L. Many people go the delid route. You can if you want. But I suggest first ruling out a bad mounting of the D9L. Do a few mock mounting and check the paste spread pattern to see if it is evenly spread. Make sure to tighten the 4 screws in a 1-3-2-4 criss cross order and only make 1-2 turns at each screw position sequentially.

2) To me, a difference of 10C between having the top/side panels on and off means case ventilation is non desirable. If you are using 2-fan D9L as intake from the rear and your display card is a blower card, then there is no active case exhaust and this might be the chief reason explaining why such a big delta (10C). Need to do something about this issue. Say, first try to reverse the 2 fans of D9L from rear intake to rear exhaust (assuming you still use a blower display card).

3) this is probably a small problem but you can 'fine tune' the core voltage by undervolting a little. Your current max of 1.305v, by my causal search, is slightly high. Sometimes the motherboard sends 'more than enough' voltage to the CPU to ensure stability, thus causing higher temp. So, do it by small increment, say, -0.025v. Undervolting would not hurt your hardware, just giving BSOD when it becomes unstable. I think, if you can get it down to 1.28v, then it will have a big improvement.

18C ambient is a very cool temp and it should give much lower temp than what you are having now.
 
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