As a budget board, one never expects to get a premium power solution and of course there isn’t one here. That it isn’t premium however doesn’t mean it isn’t functional. To that end ASRock has outfitted the B450M Steel Legend with a 4+2 phase configuration. The controller of choice the four-phase max, uPI uP9505P driving SinoPower MOSFETS. I am unsure how much power this setup can deliver but it was enough for the Ryzen 7 3800X used for testing and according to the CPU support list even the Ryzen 9 3950X is supported. So, make of that what you will.
When overclocking this motherboard or the CPU and memory ont his motherboard rather, I noticed some lower than expected multi threaded performance. I’m unsure if this is related to power, but seeing as that in lightly threaded workloads this board was incredibly fast, I so suspect it is related to power. However I can’t confirm that. It is also to be noted that these performance discrepancies are when the CPU is heavily overclocked in conjunction with the memory. Under normal operation or moderate tuning this isn’t an issue.