Skip to main content

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

Introduction and Test System

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 CPU cooling. Setting CPU frequencies too high or voltages too low aren’t the only variables that negatively affect a competitive 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
SystemCore i7-8700Z370 Gaming Pro Carbon ACTrident Z 16GB (2x 8GB) @3200MX300 SSD 1050GBDark Power Pro 10 (850W)
CoolingAlphacool Eisblock XPXAlphacool Eiszeit 2000 ChillerThermal Grizzly Kryonaut used when switching coolers
CaseMicrocool Banchetto 101
GraphicsROG Strix RX560 04G Gaming 4GB
MonitorEizo EV3237-BK
Power Consumption MeasurementContact-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 Measurement1x Optris PI640 80 Hz Infrared Camera + PI Connect Real-Time Infrared Monitoring and Recording
Operating SystemWindows 10 Pro 1709, All Updates


MORE: Intel & AMD Processor Hierarchy

MORE: All CPUs Content