[SOLVED] What is the best way to throttle the power on the i9 9900k Turbo?

Semp

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Jun 7, 2015
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So I've had this problem since I got it (yikes, yes, I know):
The i9 9900k I've got runs at 95-110*c if put to 100% utilisation with Turbo on.
Playing demanding games it will be anywhere from 5-80% utilisation, so this isn't a problem in normal use, as it will be anywhere from 60-75*c
Idle temps are 30-35*c.

Turning Turbo OFF so its back at 3.6Ghz, it wont ever go past 60*c on prime95 max or anything else utilising 100%.

Cooled with the h150i Pro AIO.
Both CPU, Mobo and AIO where new when this problem was diagnosed.
Since then, I've just somewhat ignored it as I never reach 100%.

What I want to know is if there is a way to reduce the turbo so that it doesnt cook itself when it gets over 90%.

I've re-seated my cooler several times with different thermal paste techniques, cleaning properly every time etc and same result every time. The non turbo test I think proves that the cooler is working somewhat as expected, its just not good enough for the i9 9900k at its 100% (but absolutely fine below that).

Corsair link reports AIO fans are running at 1500-1600 RPM and Pump is running at around 2800ish when at max.

Only thinking this is a problem now as I've started playing some badly optimised games that will put 100% utilisation on the CPU when travelling long distances.
Oddly enough even when going through absolutely nuts temperatures, everything seems stable and responsive, frame-rate continues unimpeded.

This is all at stock settings, the only thing I've ever changed is the Turbo ON/OFF, and the Corsair Link profile to Performance, so the fans would be up to their max.

If I'm just an absolute idiot please let me know. I cant really make heads or tails of this problem.

If the answer is anything overclocky please explain it like I'm 5 as I've never done any... underclocking(?) before.

Specs:
i9 9900k
Asrock Phantom Gaming 9 Mobo
Nvidia GTX 1080ti
Corsair h150i Pro (360mm radiator)



Corsair Link report - load was 100% at the time of this screenshot, just as the test ended so it looks like 71%
 

Semp

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Jun 7, 2015
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I'm guessing you're testing with AVX on in Prime95. Hardly any consumer-level workload uses AVX.

Look in your BIOS for "AVX offset" CPU multiplier
Ok you're my hero.

I'd read about this earlier today but discounted it as people wrote about how rare it's usage was, and the fact I'd first seen this happening was during Blender Render in Cycles - something I only now just discovered (because you suggested it) uses AVX. Dual Universe (the game I'm currently having problems with) must be using it, as they're doing some fairly nutty things with unbelievably large voxel worlds. I decided to test with Prime just today because others were doing so.

I was considering buying an entirely new cooler just because I was out of ideas.
You may have just saved my machine from a hot death, and saved me a bunch of money.

I really hope you can go the rest of your day feeling good about yourself, because you deserve it.
 

Semp

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Jun 7, 2015
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For anyone that has the same problem, setting the AVX Offset Ratio to "3" in the ASROCK Phantom Gaming 9 BIOS results in a drop to 4.39GHz during AVX use, and at 100% utilisation results in 75°c... instead of 115°c.
Value of 2 results in 80 - 85°c, which was still a tad too hot for my liking.
 

tennis2

Distinguished
Hey, just here to help. But we might not be out of the woods yet. Just because we improved the behavior, doesn't mean we've fixed/identified the problem.

I'd have to dig some to verify, but I feel like a 360mm rad should be able to keep a 9900K below 85C at stock/auto clocks even under AVX workloads. Might want to try a few "troubleshooting" steps. I'll try to list them in order of easiest to most involved:
  1. Provide us with your case brand/model, what fans you have where, and which way are the fans blowing air. Where is your AIO mounted, and which way is it blowing?
  2. Is the AIO pump header set to run the pump at 100% duty cycle at all times? (seems like yes, per OP) Maybe the AIO is low on fluid, or there's an air bubble near the CPU block...
  3. Have you tried a manual "CPU voltage offset" in your BIOS. Set progressively greater negative values, and stress test for 10 minutes at each voltage until you reach instability. Then bump it back up a bit. At that point, you'll have optimized for the lowest stable power/heat output at your desired frequency.
  4. Maybe the AIO isn't mounted tight enough, or maybe there's too much or too little thermal paste. (this is potentially less time consuming than step 3, but requires removing the AIO block from the CPU). Again, seems like this is confirmed ok per your OP.
https://www.anandtech.com/show/13400/intel-9th-gen-core-i9-9900k-i7-9700k-i5-9600k-review/22

See how the "auto" setting resulted in the same power consumption as they got 4.9GHz all core. Not sure why temps were so much lower, despite the same power consumption though....

I'm not 100% certain, but according to Anandtech's "test setup" page, they're using a 120mm tower-style heatsink "TRUE Copper". Their test are almost certainly done on an open test bench, and NOT inside a case. Most reviewers don't test in cases.
 
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