Power Delivery Thermal Analysis

A lot more focus has been put on power delivery specifications and capabilities, not just by manufacturers but as a result of users' demands. In addition to the extra power benefits from things like overclocking, more efficient designs in power deliveries and cooling solutions aim to bring temperatures down. Although this isn't something most users ever need to worry about, certain enthusiasts are bringing more focus onto each board's power delivery. The more premium models tend to include bigger and higher-grade power deliveries, with bigger and more intricate heatsink designs, with some even providing water blocks, while others are spending more just to make sure the most efficient parts on the market are being used.


The 16-phase power delivery on the ASUS ROG Maximus XIII Hero (operating at teamed 7+1)

Testing Methodology

Our method of testing is if the power delivery and its heatsink are effective at dissipating heat. We do this by running an intensely heavy CPU workload for a prolonged method of time. We apply an overclock which is deemed safe and at the maximum that the silicon on our testbed processor allows. We then run the Prime95 with AVX2 enabled under a torture test for an hour at the maximum stable overclock we can which puts insane pressure on the processor. We collect our data via three different methods which include the following:

  • Taking a thermal image from a birds-eye view after an hour with a Flir Pro thermal imaging camera
  • Securing two probes on to the rear of the PCB, right underneath CPU VCore section of the power delivery for better parity in case a probe reports a faulty reading
  • Taking a reading of the VRM temperature from the sensor reading within the HWInfo monitoring application

The reason for using three different methods is that some sensors can read inaccurate temperatures, which can give very erratic results for users looking to gauge whether an overclock is too much pressure for the power delivery handle. With using a probe on the rear, it can also show the efficiency of the power stages and heatsinks as a wide margin between the probe and sensor temperature can show that the heatsink is dissipating heat and that the design is working, or that the internal sensor is massively wrong. To ensure our probe was accurate before testing, I binned 10 and selected the most accurate (within 1c of the actual temperature) for better parity in our testing.

To recreate a real-world testing scenario, the system is built into a conventional desktop chassis which is widely available. This is to show and alleviate issues when testing on open testbeds which we have done previously, which allows natural airflow to flow over the power delivery heatsinks. It provides a better comparison for the end-user and allows us to mitigate issues where heatsinks have been designed with airflow in mind, and those that have not. The idea of a heatsink is to allow effective dissipation of heat and not act as an insulator, with much more focus from consumers over the last couple of years on power delivery componentry and performance than in previous years.

For thermal imaging, we use a Flir One camera to indicate where the heat is generated around the socket area, as some designs use different configurations and an evenly spread power delivery with good components will usually generate less heat. Manufacturers who use inefficient heatsinks and cheap out on power delivery components should run hotter than those who have invested. Of course, a $700 flagship motherboard is likely to outperform a cheaper $100 model under the same testing conditions, but it is still worth testing to see which vendors are doing things correctly. 

Thermal Analysis Results


We measured 53.3ºC on the hottest part of the CPU socket during our testing

The ASUS ROG Maximus XIII Hero is using a 16-phase power delivery using teamed power stages, with an Intersil ISL69269 PWM controller operating at 7+1. ASUS's power stage of choice for the CPU VCore section is the Texas Instruments 95410RR 90 SPS and includes fourteen of them teamed in pairs. For the SoC section, there's two slightly lower grade Texas Instruments 59880 70 A power stages. Cooling the large power delivery is a large and weighty L-shaped VRM heatsink, which is interconnected via a heat pipe, and should, in theory, keep the power delivery running cool even with heavier CPU overclocks.

Taking a look at our VRM thermal testing results on Z590 models tested so far, the ASUS ROG Maximus XIII Hero performs brilliantly against the competition. We saw the lowest temperatures so far, with a reading of just 55ºC from the integrated thermal sensor. This is backed up by the readings from our pair of K-type Thermocouples with readings of 52ºC and 54ºC respectively, and again, is backed up by our FLIR thermal imaging camera which measured 53.3ºC on the hottest part of the power plane.

While a lot of models tested so far have dumped the majority of the heat into the power plane around the power delivery, the Hero is effectively drawing heat out via the large heatsinks and is also aided by the efficient 16-phase (7+1) teamed power delivery.

Overall it's a fantastic result for ASUS and shows the true efficiency and design prowess of ROG's R&D team.

Overclocking ASUS ROG Maximus XIII Hero Conclusion
Comments Locked

28 Comments

View All Comments

  • Oxford Guy - Sunday, July 11, 2021 - link

    14nm.
  • Oxford Guy - Sunday, July 11, 2021 - link

    Everything for Rocket Lake except the relevance.
  • DarkSpatter - Sunday, July 11, 2021 - link

    How can you have a 16 phase VRM running in 7.1? I think you mean the board has 16 smart power stages & inductors, with two of each assigned to 7.1 phases?
  • Dr_b_ - Tuesday, July 13, 2021 - link

    Had this board, one month in, it died and wouldn't boot. Could be the CPU, but only have one, so RMAd it.

Log in

Don't have an account? Sign up now