I also try to do an idle / light load test and see how the Eco PBO 65W mode compare to the good old static 1.025v 4.8Ghz cool and quiet mode. I try to make it as fair as possible on both idle and light load test by not doing anything else. Both obviously include the capturing software usage, so probably not so fair to the PBO side.
The Eco mode simply cap the PPT as it makes no attempt to lower the overvolted 1.3-1.4 vcore when core speed is only in the 1-4Ghz range. It usually burn 15-25W CPU power. I don't know if it's a limitation because it may degrade the cpu quickly if AMD set it to 1v on low speed and spike to ~1.4-1.52v quickly and repeatedly.
The manual 1.025v static 4.8GHz uses ~7-9W CPU power.
Light load test on streaming quote from Tradingview on 1 Chrome window only
The Eco mode light load test use ~28W on avg, spike to ~46W max CPU power.
The manual 1.025v static 4.8GHz use ~9-12W on avg, spike to 18W max CPU power.
Using Asrock Blazing OC Tuner 1.04 to test, the feature is a bit limited. Although I can set either static OC or PBO mode manually, it does not provide a way to set this by schedule to define how it would run automatically. Also it would have been excellent if I can just right click on systray and select the OC or PBO mode easily instead of opening it up like this.
Since I use this as a 24/7 server/vm/gaming comp, it seems to be more efficient to just set static OC manually most of the time, forget about Eco mode, and only turn on PBO mode through the App when gaming.