The EVGA Z590 Dark Motherboard Review: For Extreme Enthusiasts

Power Delivery Thermal Analysis

One of the most requested elements of our motherboard reviews revolves around the power delivery and its componentry. Aside from the quality of the components and its capability for overclocking to push out higher clock speeds which in turn improves performance, is the thermal capability of the cooling solutions implemented by manufacturers. While almost always fine for users running processors at default settings, the cooling capability of the VRMs isn't something that users should worry too much about, but for those looking to squeeze out extra performance from the CPU via overclocking, this puts extra pressure on the power delivery and in turn, generates extra heat. This is why more premium models often include heatsinks on its models with better cooling designs, heftier chunks of metal, and in some cases, even with water blocks.

The 21-phase power delivery on the EVGA Z590 Dark (operating in 8+1+1 with doublers for the CPU VCore)

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 65.1ºC on the hottest part of the CPU socket during our testing

The EVGA Z590 Dark is using a large 21-phase power delivery system, which is actually operating in an 8+1+1 configuration. The CPU VCore section consists of sixteen Renesas ISL99390 90 A smart power stages operating in an 8-phase layout with eight Renesas ISL6617 doublers, while the SoC section is using one Renesas ISL99360 60 A power stage. Keeping the power delivery cool is a large pair of heatsinks that are interconnected by a single heat pipe which also connects it to the chipset heatsink. To further aid in heat dissipation, EVGA includes two 40 mm cooling fans that vent hot air out via ventilation holes in the pre-attached rear I/O shield.

Focusing on the thermal performance of the EVGA Z590 Dark's power delivery, it put in a solid performance despite not operating as cool as some other Z590 models we have tested. It trades blows with the equally adept GIGABYTE Z590 Aorus Tachyon, but the EVGA board does have the added advantage of an actively cooled VRM design. We observed temperatures of 71°C from the integrated thermal VRM sensor, with temperatures of 74°C and 72°C respectively from our pair of K-type thermocouples. 

Overall the EVGA Z590 Dark does perform well, but we would have expected better given the pair of cooling fans and the large heatsink design, as well as the large design of the power delivery.