Power and Overclocking
Run via the IGP for graphics duties, both platforms are remarkably frugal on the old juice. We can see users opting for passive PSUs and quiet fans for a largely noise-free experience.
Overclocking
We managed to increase the CPU speed to an all-core 4.0GHz while overclocking the IGP - and the resultant speed staying active - required installing AMD's Ryzen Master utility, which increased the IGP speed from 1,250MHz to 1,500MHz. Being even handed in these charts, the comparison Core i3-8350K was overclocked too, with the CPU running at a much higher 5.0GHz all-core frequency and IGP at 1,400MHz.
Compared like for like, the Ryzen 5 2400G's extra threads and much, much faster IGP win out.