How to Stress-Test CPUs and PCs (Like We Do)

By Igor Wallossek
last updated

Is it getting hot in here?

CPU Only: Measuring Temperatures With Different Stress Tests

Next up: temperatures. These are directly related to the waste heat dissipated during our stress tests. Various workloads push different parts of the CPU in unique ways, yielding more interesting findings than we were expecting.

Core temperatures are measured by the CPU’s integrated digital thermal sensor (DTS), which reacts to actual load levels on an almost real-time basis. Between this and our chiller-based cooling solution, which maintains its fluid at a near-constant 20°C, we get very accurate load measurements. Then, we calculate the average temperatures across all cores throughout our test run.

Package temperature, or, more precisely, the reading provided by the platform environment control interface (PECI), is typically similar to the average core temperature.

Once again, we calculate the average across the entire 30 to 45 minutes it takes for the temperature to stabilize. While the results usually come close to the respective core temperatures, they do exceed them in certain circumstances, depending on the type of test.

Next, we examine data from an additional sensor located directly underneath the socket. Since the CPU cooler does its job from the top, through a heat spreader, this second sensor's more sluggish result provides important information about stability and cooling performance. Using Prime95, the CPU hits a whopping 105°C without any overclocking, and in spite of the chiller!

This result demonstrates why you want to use Prime95 with AVX as a stability test for an extended period of time only if you're using monitoring software that can track all relevant temperatures.

In the end, knowing that the CPU (DTS) is cooled well doesn't really matter if the package underneath is burning up.

The memory load varies quite a bit between tests, as well. Here are all of the measurement results in one bar graph for direct comparison:

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Igor Wallossek
9 Comments Comment from the forums
  • WINTERLORD
    Is this like a fancy water cooler im guessing? what about a typical AIO cooler. In fact i have a skyth fuma but may save up to get some kind of AIO water cooling been tryin to find decent reviews on decent water coolers both cheap and if needed high end. not no alpha cooler though lol
    Alphacool Eisblock XPX ($73.99 On Newegg)
    Alphacool Eiszeit 2000 Chiller
    Reply
  • FormatC
    This is a high-end compressor cooler for up to 1500 watts heat input. It's a modified version from industry and mostly used to cool the head of powerful laser cutters. Why I'm using this one? To show, which program is able to do it right. If you have additionally limitations from coolers, thermal throttling and other funny things, you will never see the exact difference. I can keep a constant water temperature of 20°C to make all the test results comparable. ;)
    Reply
  • Th_Redman
    What did you guys put on the hotdog after testing? A little mustard, ketchup, relish, sauerkraut...? LOL.
    Reply
  • WINTERLORD
    is actually a great article one can resort reference too. Good Job!
    Reply
  • aquielisunari
    I use Aida, Prime 26.6, Superposition, UserBenchmark, MSI's kombustor and I no longer use Heaven. I may be forgetting a couple. But something has always felt a little off. I finally see what it was. My build was missing a hotdog and its bun. I always do love learning from the pros. I placed it on a piece of parchment and instantly I notice a difference.

    I routinely check temperatures, loads and other info from my system. I also stress test with different CPU and GPU benchmark/stress test software. Thanks for the info. Page bookmarked.
    Reply
  • CompuTronix
    As the author of the Intel Temperature Guide - http://www.tomshardware.com/forum/id-1800828/intel-temperature-guide.html - I can fully appreciate how much work went into creating this outstanding article, which has been sorely needed!

    Since most users test their rigs without a sense of scale for power and temperature, they can't compare apples to apples, especially when combined with major variables such as differences in ambient temperature, hardware configurations and software utilities. This article provides a perspective and some excellent comparisons.

    The Intel Temperature Guide differs in its approach toward the topic of processor Core temperatures and cooling with respect to Intel's TDP specifications, and distinguishes between steady workloads for thermal testing versus fluctuating workloads for stability testing. Nevertheless, our results are very similar.

    However, since Intel validates their thermal specifications at a steady 100% TDP, it's most appropriate to select utilities that don't overload or underload the CPU. The only utilities I've ever found that come as close as possible to 100% TDP are Prime95 v26.6 Small FFT's as a steady workload for thermal testing, and Asus RealBench as a fluctuating workload for stability testing.

    Although the topic of Prime95 (with and without AVX) was covered, I would like to have seen RealBench included in your test suite,since it's widely accepted as an excellent utility for testing overall system stability, and uses a realistic AVX workload.

    Otherwise, great work! I was very pleased to read this article!

    CT :sol:
    Reply
  • cangelini
    20741319 said:
    As the author of the Intel Temperature Guide - http://www.tomshardware.com/forum/id-1800828/intel-temperature-guide.html - I can fully appreciate how much work went into creating this outstanding article, which has been sorely needed!

    Since most users test their rigs without a sense of scale for power and temperature, they can't compare apples to apples, especially when combined with major variables such as differences in ambient temperature, hardware configurations and software utilities. This article provides some excellent comparisons.

    The Intel Temperature Guide differs in its approach toward the topic of processor Core temperatures and cooling with respect to Intel's TDP specifications, and distinguishes between steady workloads for thermal testing versus fluctuating workloads for stability testing. Nevertheless, our results are very similar.

    However, since Intel validates their thermal specifications at a steady 100% TDP, it's most appropriate to select utilities that don't overload or underload the CPU. The only utilities I've ever found that come as close as possible to 100% TDP are Prime95 v26.6 Small FFT's for thermal testing, which is a steady workload, and Asus RealBench for stability testing, which is a fluctuating workload.

    Although the topic of Prime95 (with and without AVX) was covered, I would like to have seen RealBench included in your test suite, as it's widely accepted as an excellent utility for testing overall system stability, and uses a realistic AVX workload.

    Otherwise, great work! I was very pleased to read this article!

    CT :sol:

    That's an awesome resource, CT!
    Reply
  • WyomingKnott
    20740696 said:
    What did you guys put on the hotdog after testing? A little mustard, ketchup, relish, sauerkraut...? LOL.

    Thermal compound. Why not? People have used condiments between their CPUs and their coolers.
    Reply
  • FormatC
    Step 1 - Collect all what I need:

    Step 2 - Start the oven

    Step 3 - Enjoy!
    The benchmark:


    The complete review was so funny, but it was never translated :(
    Reply