I have a 3200G and I limit it to 35W(of 3 built-in values, 64, 45 and 35) since I run it off a picoPSU. Haven't done much testing without the power limits, but it's plenty peppy at 35W.
These lower power limits reduce performance a lot on chiplet CPUs (unlike your monolithic APU). The impact is maybe a little less crass on Zen 4 because the 7nm IOD seems to use less power than the old 12nm one used in Zen 2/3.
For example, a 5600X in CB R20
PPT Freq Points (nT) Core power
82 W 4500 MHz 4350 54 W (stock)
65 W 4200 MHz 4000 43 W
38 W 2500 MHz 2400 17 W (lowest allowed)
The SoC/uncore consumes around 15-20 W on Zen 2/3, so at 38 W you only leave 15-20 W for the actual CPU part of the CPU. Meanwhile the low-load and idle savings are essentially nil because all of the idle power is the IOD/uncore.
For example, a 5600X in CB R20
The SoC/uncore consumes around 15-20 W on Zen 2/3, so at 38 W you only leave 15-20 W for the actual CPU part of the CPU. Meanwhile the low-load and idle savings are essentially nil because all of the idle power is the IOD/uncore.