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

We hope you learned something interesting from How to Stress-Test Graphics Cards (Like We Do). In that piece, we introduced monitoring software, real-world games, synthetic benchmarks, and artificially intense workloads that the Tom's Hardware team uses in our laboratories around the world to enhance coverage of graphics cards.

Now it's time to explore host processing and platform-oriented testing, including the apps needed to evaluate stability and cooling. Setting frequencies too high or voltages too low aren’t the only variables that negatively affect your overclock. Temperatures play a major role, too. So, how do you stress test your own CPU thoroughly (yet safely), and which utilities should you use for this purpose?

Important Warning about All Stress Tests

Before we begin, we need to warn our readers about the inherent dangers of running stress tests. The software that we’re presenting might not just produce a full load, but also potentially push beyond manufacturer-defined power limits. Using these so-called "power viruses" can result in damage to the system, especially if they're used for extended periods of time. Those who want to use these applications assume all responsibility for the outcome. Be sure to continuously monitor relevant parameters, including temperatures, with accurate and up-to-date utilities. At least you'll be able to abort your testing immediately if it becomes necessary.

Choosing the Right Monitoring Application

How to Stress-Test Graphics Cards (Like We Do) covered a lot of the software we use for monitoring graphics card health. Keeping an eye on your platform's vitals may require a different approach, though. After all, there are a lot more sensors to watch.

HWiNFO64 is a good example of a tool that can do all of this. It can read practically any sensor output and write it to a file in real time. However, the sensor loop tends to lag due to its sheer number of readings. Even one-second intervals don't always prevent a lag in the time stamps. Download HWiNFO64 here.

Consequently, our recommendation is to not just hide unnecessary sensor readings (network, system, drives, etc.), but to exclude them from the loop altogether. This makes for a less cluttered display and gets rid of the aforementioned lag, even using 500ms intervals.

Choosing the Right CPU

We’re not using the familiar X299- and X99-based systems this time around. Instead, we're testing with an Intel Core i7-8700 and Z370 motherboard with 16GB of DDR4-3200 memory. This configuration represents high-end hardware fairly well, including the fact that gaming machines tend to lack some of the monitoring capabilities available on workstations.

However, our Alphacool Eiszeit 2000 Chiller generates a water temperature of exactly 20°C for us, as usual. This is what makes a direct comparison between different stress-testing applications possible.

The same Asus ROG Strix Radeon RX 560 from our previous stress testing story makes another appearance today. That means our results are comparable. Faster graphics cards don’t change our conclusions in any meaningful way; they just increase power consumption.

Test System and Methodology

We introduced our new test system and methodology in How We Test Graphics Cards. If you'd like more detail about our general approach, check that piece out. We've adjusted the CPU and the cooling system to better suit this article.

The hardware used in our lab includes:

Test Equipment & Environment
System Intel Core i7-8700 ($312.00 On Amazon)
MSI Z370 Gaming Pro Carbon AC ($199.99 On Amazon)
G.Skill Trident Z 16GB (2x 8GB) ($178.00 On Amazon) @3200
Crucial MX300 1TB ($189.99 On Amazon)
be quiet! Dark Power Pro 11 850W ($199.00 On -)
Cooling
Alphacool Eisblock XPX ($73.99 On Newegg)
Alphacool Eiszeit 2000 Chiller ($1076.29 On Newegg)
Thermal Grizzly Kryonaut ($11.99 On Amazon) used when switching coolers
Case
Microcool Banchetto 101
Graphics
Asus RX 560 Strix OC ($139.99 On Amazon)
MonitorEizo EV3237-BK
Power Consumption
Measurement
Contact-free DC Measurement at PCIe Slot (Using a Riser Card)
Contact-free DC Measurement at External Auxiliary Power Supply Cable
Direct Voltage Measurement at Power Supply
2x Rohde & Schwarz HMO 3054, 500 MHz Digital Multi-Channel Oscilloscope with Storage Function
4x Rohde & Schwarz HZO50 Current Probe (1mA - 30A, 100 kHz, DC)
4x Rohde & Schwarz HZ355 (10:1 Probes, 500 MHz)
1x Rohde & Schwarz HMC 8012 Digital Multimeter with Storage Function
Thermal
Measurement
1x Optris PI640 80 Hz Infrared Camera + PI Connect
Real-Time Infrared Monitoring and Recording
Operating System
Windows 10 Pro USB ($199.99 On Amazon) 1709, All Updates

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  • 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
  • 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. ;)
  • Th_Redman
    What did you guys put on the hotdog after testing? A little mustard, ketchup, relish, sauerkraut...? LOL.
  • WINTERLORD
    is actually a great article one can resort reference too. Good Job!
  • 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.
  • 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:
  • cangelini
    Anonymous 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!
  • WyomingKnott
    Anonymous 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.
  • 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 :(