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 MEG X570 ACE, one probe is placed on the left bank of Vcore power stages. Another goes on the top row of Vcore power stages, and one on the chipset. 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 variation in ambient temperature, including changes over the course of a test, while presenting the data as if the ambient were a steady 20 °C for easier presentation. 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 have switched to listing the highest temperature recorded in my normal benchmarking suite. 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 MEG X570 ACE thwarted my best attempts to make it thermal throttle. Interestingly, this VRM idled at a higher temperature, but had a much flatter curve in the torture test. However, I don't think my Ryzen 5 3600X ever posed any threat. Hopefully, I can get my hands on a 3900X soon, as well as a 3950X eventually, as those are the processors most X570 VRM are designed around.
The chipset heatsink, while not the most massive I have seen, is aided by the heatpipe connection to the VRM heatsink. The fan was quiet throughout testing, and the fan curve can easily be adjusted in the BIOS.