I was temporarily using an RX 460 while I RMA'ed my Asus RX470 strix. The RX 460 was a great card for the money was pretty much able to play any game just fine. I was messing around with it one day and noticed that when watching a video, it was using quite a bit of power relative to how much it uses when at max utilization. Card would use 50w when play Mass Effect Andromeda 100% usage for example and then almost 20w at like 6% usage, I didn't think that made sense. Then I turned on Power Efficiency in Radeon settings and that power usage while watching video dropped to like 7w and didn't notice any thing different during gameplay.
When I got my RX 470 back yesterday, I decided to do the same thing because it was following the same trend as the 460 and didn't want to gpu fan spinning up while watching a video. So I turned Power Efficiency on and it was fine on desktop and videos and such but in game, it turned my RX 470 into a choppy mess with this option enabled. Also I noticed that on the RX 470 the clock speed drops to 300MHZ frequently when playing a game that puts a full load on the GPU, this didn't happen with the 460.
Obviously there is an issue here. Is this a known issue, will it be fixed? I would like to use this option but right now, there's no way this option is usable on the RX 470 in it's current state.
i'm on driver version 17.5.2