Power Consumption and Temperatures

For temperature measurement, I 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 Gigabyte B550M AORUS Pro, one probe is centered along each bank of 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 end 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 easy 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 am now using Prime95's Small FFT test for power consumption. For temperatures, I am using the maximum temperatures recorded over the course of my standard benchmark suite, which almost always occur during either wPrime or Blender. 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.

This test typically involves a 30 minute Prime95 run at the maximum overclock the motherboard can maintain, again with no airflow over the VRM. For B550, I chose 4.2 GHz at 1.35 V as the most intensive load I could manage in long tests without thermal throttling the CPU. 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.


The Gigabyte B550M AORUS Pro struggled in my VRM torture testing, reaching over 90 °C and exhibiting some throttling. I have to give the B550M AORUS Pro credit, though. Even after it started throttling, the clock stayed at 4.2 GHz most of the time with only short dips in frequency.

Given the price point, this is an acceptable result. It would not be reasonable to expect perfect overclocking performance with a US$400 CPU on a US$130 motherboard.