Question periodic spikes in temperature when under load

Aug 3, 2019
When I'm stresstesting my cpu, I have periodic spikes in temperature and tdp usage. The same happens under normal usage, but its harder to verify and test with differing cpu utilization.

That screenshot shows the temperature graph while stresstesting with IETU. The temperature ranged from 62 to 82 with an OC of 5ghz and the spikes happen every 2 seconds.
My setup is: asus rog maximus x hero, 8700k, 32gb ram
OC were for example 4.8@1.26V, 5.0@1.3V and default settings.
Cooling is NZXT kraken x62 i think
Above settings didnt change the periodic temperature spikes, just the range was different
I have also tried reapplieing thermalpaste.
Hoping for solutions, glazor



On behalf of Tom's Moderator Team, welcome aboard!

IETU is a fluctuating workload, which is precisely why you're seeing fluctuating Core temperatures. If you instead run a steady-state workload, you'll see steady Core temperatures.

The "Charts" in SpeedFan span 13 minutes, and show how each test creates distinct thermal signatures.

Shown above from left to right: Prime95 Small FFT's, Blend, Linpack and IntelBurn Test.

Note the steady thermal signature of Small FFT's, which allows accurate measurements of Core temperatures. A steady 100% workload is key for thermal testing so the CPU, cooler, socket, motherboard and voltage regulators can thermally stabilize.

Shown above from left to right: Prime95 Small FFT's, Intel Extreme Tuning Utility CPU Test, and AIDA64 CPU Test.

“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 (AVX 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 (AVX 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.

We actually have a Guide for this topic: Intel Temperature Guide -

It's a "Sticky" near the top of the CPUs Forum; if you look there you can't miss it. I suggest you read the entire Guide, but pay especially close attention to Section 11 - Thermal Test Basics.

Once again, welcome aboard!

CT :sol: