[SOLVED] i7-9700k unusually high temperatures with a load of cooling, would really appreciate input

thelynx

Honorable
Jun 18, 2015
13
0
10,510
Hi, I built my PC about three years ago and have been struggling to get adequate noise levels and temperatures ever since with my 9700k. I started with two stock fans and a Cryorig H7 and have since upgraded a number of components which are the following:

i7-9700k (stock/4.6ghz turbo) (undervolted)
NH-D15s
Z390 Aorus Pro WiFi
Thermal Grizzly Kryonaut
RTX 3070 Noctua Edition (stock)
S340 Elite
RM 650x
Silent Wings 3 120mm x3
Silent Wings 3 140mm x1
970 Evo
2TB Barracuda

Thermal paste was applied very carefully and spread out generously using the included spatula. I reapplied it twice with my H7 before I got the NH-D15s.

Temperatures hover around 65-70c on both CPU and GPU in most games after only 30 mins. In some games such as MSFS the CPU hits 80c on spikes while maintaining 70c with the GPU solid at 70c after only 30 mins. HWInfo seems to indicate CPU going to max 1.3v at only 4.5-6ghz. This seems high considering it was undervolted, maybe I am misunderstanding how undervolting in the BIOS works.

These temperatures seem okay but considering I have so much cooling and have spent quite a lot on what I thought were the coolest components and having not touched the CPU or GPU overclock with a top of the line air cooler and the 4.3 slot Noctua 3070, they seem quite high, especially that the PC is a bit louder as the fans are working fairly hard. Whereas my brother's PC which only has a 8600k but a 212 Evo, runs dead silent with stock NZXT fans and MX-4 at 50c max absolutely caked in a thick layer of dust.

Any help would really be appreciated, I understand there's not a whole lot to go on but this has been frustrating me and my wallet for years.
 
Solution
Some games are more demanding than others, with CPU load increased at 1080P with a very healthy GPU, which a 3070 certainly qualifies as...

Run HWMonitor, to monitor all core clock speeds under load, and then Prime95 (version 29.8), select 'Small FFTs', then disable AVX and AVX2 on bottom tabs, and run it for 10-15 minutes noting temps, core voltage, and clock speeds as displayed in HWMonitor. (P95/small FFT-loaded CPU temps are considered 100% loads, and certainly give higher temps than most all games ever would, but, it's an apples-to-apples' comparison)

My own aging 7700K (with single fan NH-D15) running overclocked at 4.7 GHz all-core turbo, MCE-enabled. starts at 69C in this test quite quickly, but, will climb to ~75C after 10...
Those are pretty decent numbers considering they are under load readings. You do have everything top of the line except the case. That case is holding up to its potential and I don't think it can push any more. A lot depends on the ambient too. But all said and done, those are pretty good numbers and I would be satisfied with them if I were you.
 
Some games are more demanding than others, with CPU load increased at 1080P with a very healthy GPU, which a 3070 certainly qualifies as...

Run HWMonitor, to monitor all core clock speeds under load, and then Prime95 (version 29.8), select 'Small FFTs', then disable AVX and AVX2 on bottom tabs, and run it for 10-15 minutes noting temps, core voltage, and clock speeds as displayed in HWMonitor. (P95/small FFT-loaded CPU temps are considered 100% loads, and certainly give higher temps than most all games ever would, but, it's an apples-to-apples' comparison)

My own aging 7700K (with single fan NH-D15) running overclocked at 4.7 GHz all-core turbo, MCE-enabled. starts at 69C in this test quite quickly, but, will climb to ~75C after 10 min....

(A 9700K /Z390 Prime build for a friend I built a couple years ago had slightly higher temps at 80C even at 4.6 GHz all core/MCE-enabled under this workload, just as a point of comparison, so yours is really not 'out of line' in my opinion, as the one i tested did run warmer than my 7700K does)
 
Solution
What is the fan arrangement for your case?
I would think that two 140mm fans should be used to supply the maximum amount of fresh air.
Noctua makes nice and quiet 140mm fans.
Think of it this way:
One 140 to supply cooling air to the NH-D15s
One 140 to supply cooling air to the fans on the graphics card.

In time, all of the intake air will exit the system somewhere, taking component heat with it.
The main purpose of the rear 120 exhaust is to direct the airflow past the cpu cooler.
Top exit fans may be counter productive by inducing the airflow to exit the case and bypass the cpu cooler.
Try disconnecting them and see if it makes any difference.
Binning history of the 9700K indicates that 100% should be able to reach 4.9. Seems a bit high to me:
https://siliconlottery.com/pages/statistics

Long time ago, I used a slot fan located just below the graphics card.
It looked like this, except it had a speed knob to tune the fan speed.
https://www.amazon.com/StarTech-com-Expansion-Exhaust-Cooling-Connector/dp/B0000510SS
The benefit was to help draw some of the front cooling air past the graphics card.
As I recall, it helped.