German overclocker der8auer investigated the power draw and concludes that unlike previous expectations, it doesn't seem like PCI Express 4.0 is the culprit here. Hexus provides a summary of the video over here:
Der8auer is surprised by how little difference there is between NVMe Gen 3 and 4 under load in terms of power consumption "because everybody kept telling us (at Computex) that the chipset has much higher power consumption because of PCI Express Gen 4." In summary the OC expert couldn't pin down why the chipset requires so much extra power in actuality. Hopefully things will become clearer as boards are tested by more tech review sites like ourselves, it is still early days.
Another article about the high power consumption of the X570 motherboards can be read at ExtremeTech. This site suggest the X570 motherboards draw so much power that they're warping CPU comparisons. As it stands right now, the difference between the AMD Ryzen 7 3700X in the MSI X570 Godlike versus the X470 Gaming M7 AC is a whopping 38W when running Prime95! At the moment, it's not clear why the X570 motherboards draw so much power and if this can (partly) be fixed via future UEFI updates.
The original title of this story, “AMD’s X570 Chipset Draws So Much Power, It’s Warping CPU Comparisons” implied that the power draw differential is entirely a function of the X570 chipset itself. This was an unintentional inaccuracy. It isn’t the X570 chipset alone that’s drawing the additional power, it’s the entire motherboard. The actual X570 chipset only draws ~7W at load. (If the X570 chipset actually drew 30-50W, the size of the heatsink and fan on top of it would be far larger than they are).When dropping the Ryzen 7 2700X and Ryzen 7 3700X in the same motherboard, there's a difference of 90W in favor of the 3700X. Clearly, the new Zen 2-based CPUs are a lot more power efficient than the previous generation, but a lot of the improvement is taken away by the high power draw of the X570 motherboards.