Question Intel I9-9900k with Corsair H150i

Aug 1, 2019
I just recently put my pc together two weeks ago, I installed the Corsair H150i on my I9-9900k. I was having trouble keeping the cpu cool at the stock 3.6GHz under normal conditions. I swapped the included thermal paste with Artic Silver 5 and turned on the Intel turbo boost at 5.0GHz. Running prime95 my core temps get up to 95-100c within seconds. Could I have a problem with either the AIO or the Cpu?

And one more question, I hear a noise coming from the cpu which can only be explained as the sounds a hard drive would make, I don't know if that's a related problem but I would like some opinions on that.
Aug 1, 2019
Phaaze88- I am using version 29.8 AVX not disabled. I know the cpu doesn't have any moving parts but I poked around with a mechanics stethoscope and hear the noise only one the cpu load plate front and rear, definitely more on the front.

remixislandmusic- I am using Arctic Silver 5 thermal paste. Fans and pump both properly plugged in and turned to extreme performance in the Corsair ICUE application. I removed the pump the check the thermal paste contact, and it had full contact on the cpu.

Thanks you guys for the responses, this is only my second time posting on this forum and everyone has been extremely helpful.


Is there a specific reason for not wanting to disable AVX in Prime? Not many mainstream applications actually take advantage of those instructions.
Also, if you didn't have an AVX offset 'set', that would mean the cpu was also running 5.0ghz in AVX. People usually have to set an AVX offset of 2 or 3 at that frequency, because it usually crashes...
And even if it doesn't, the extra power draw and heat output will bring many a cooler - even beefy liquid ones - to their knees.

I have no idea about the noise thing though. You went over my head when you brought up the mechanics stethoscope.
Reactions: CompuTronix



The sound you're hearing originates at the pump as vibration, which can "telegraph" throughout the hardware ... all normal and expected.

Regarding Prime95, “stress” tests vary widely and can be characterized into two categories; stability tests which are fluctuating workloads, and thermal tests which are steady workloads. Prime95 v29.8 Small FFT's (with all AVX selections disabled) is ideally suited for testing thermal performance, because it conforms to Intel's Datasheets as a steady 100% workload with steady Core temperatures. No other utility can so closely replicate Intel's thermal test workload.

Utilities that don't overload or underload your processor will give you a valid thermal baseline. Here’s a comparison of utilities grouped as thermal and stability tests according to % of TDP, averaged across six processor Generations at stock settings rounded to the nearest 5%:

Although these tests range from 70% to 130% TDP workload, Windows Task Manager interprets every test as 100% CPU Utilization, which is processor resource activity, not actual workload. Core temperatures respond directly to Power consumption (Watts), which is driven by workload. Prime95 v29.8 Small FFT’s (all AVX selections disabled) provides a steady 100% workload, even when TDP is exceeded by overclocking. If Core temperatures don't exceed 85°C, your CPU should run the most demanding real-world workloads without overheating.

AVX - Advanced Vector Extension (AVX) Instruction Sets were introduced with Core i 2nd Generation CPU’s, then AVX2 with 4th Generation and AVX512 with later Generations of High End Desktop (HEDT) CPU’s as in certain X-Series, Extreme, i9’s and i7’s. Running versions of Prime95 with AVX enabled imposes an unrealistic workload which can adversely affect stability and severely overload your CPU. 2nd and 3rd Generations are less affected, but Core temperatures on 4th through 9th Generations may be over 20°C higher.

Many 6th through 9th Generation motherboards address the AVX problem by providing “offset” adjustments (downclock) in BIOS. -3 (300 MHz) or more may be needed to limit Core temperatures to 85°C. Since 4th and 5th Generations don’t have AVX offsets, you can create individual BIOS Profiles for AVX and non-AVX software. Except for a few utilities and specialized computational apps, AVX intensive real-world apps (such as rendering / transcoding) and recent games with AVX shouldn’t exceed Prime95's test workload without AVX.

As per Intel’s Datasheets, TDP and Thermal Specifications are validated “without AVX. In Prime95 versions from 27.7 through 29.4, AVX can be disabled by inserting CpuSupportsAVX=0 into the local.txt file, which appears in Prime95's folder after the first run. However, since Core temperatures will be the same as 29.8 without AVX, it's easier to just use 29.8. You can also use 26.6 which doesn't have AVX.

We actually have a Guide that covers this topic. It's a "Sticky" at the top of the CPUs Forum, so if you look there you can't miss it: Intel Temperature Guide -

I suggest that you give it a read. Pay particularly close attention to Section 11 - Thermal Test Basics.

CT :sol: