Power Consumption and Temperatures

With the test bench update, I have also overhauled my temperature measurement and methodology. For measurement, I now use a Reed SD-947 4 channel Data Logging Thermometer paired with four Omega Engineering SA1 Self Adhesive Thermocouple probes. One probe directly touches the chipset and two are placed on select power stages. The last probe actively logs the ambient temperature.

For the ASUS ROG MAXIMUS XI HERO (WiFi), one is in the center of the left bank Vcore and another on the top Vcore next to the SOC power stages. A probe is left out to log the ambient temperature. All temperatures are presented as Delta-T normalized to 20 °C, which is the measured temperature minus the ambient temperature plus 20 °C. The final result accounts for changes in ambient temperature (including those over the course of a test), while the data is presented as if the ambient were a steady 20 °C for ease of representation. Additionally, there is no longer any direct airflow over the VRM with this new setup, placing extra strain on the VRM cooling.

For the numbers seen in the chart above, I use wPrime for both temperature and power draw as it is the most intense. However, relatively short tests do not put enough strain on the system to get a look at how the VRM performs at the limit, so I added an additional test to try to thermally abuse Vcore as much as possible. It involves a 30 minute Prime95 run at the maximum overclock the motherboard can maintain, again with no airflow over the VRM. The temperatures are logged every second, and the two probes are then averaged for a cleaner presentation before subtracting the ambient to calculate the Delta-T. The results are charted below.


Between the overbuilt VRM and hefty heatsink, the ASUS ROG MAXIMUS XI HERO (WiFi) thwarted my best attempts to make it thermal throttle. It was a good ten degrees hotter than the ASRock Z390 Phantom Gaming X, the other Z390 board I have tested with this method. As both boards are far below their thermal limits, this is largely an arbitrary difference (the Phantom Gaming X is also US$40 more expensive).