My setup is the following:
CPU: i5 4460
GPU: RX 580 4GB
RAM: 2x4 GB
OS: Windows 10 with the latest updates
GPU Driver: Adrenalin 2019 Edition 19.9.2 Release date: 9/23/2019
I've noticed degraded performance in games recently so I've opened up MSI Afterburner to see what's happening. I saw that my CPU usage was pretty much 100% always while gaming which is unusual for the games I was running.
I've opened up the Task Manager to see that both the Radeon Setting: Host Application and the Radeon Setting: Host Service are hogging 25-30% CPU for themselves pretty much halving the performance of my PC even when no game is running.
I've installed this driver to check out the CoD MW beta since it couldn't run on the older one I had installed. First I uninstalled the old one with DDU and installed this one. I didn't have an issue like this with the previous driver but I've had a similar issue over a year ago and then I just had to uninstall the Intel HD driver from my PC, but I haven't reinstalled it, so that isn't the solution this time.
I've already tried reinstalling the driver after uninstalling it with DDU but it haven't solved my issue.
When you restart the computer, it is probably not a problem. Radeon Software may react similarly when you run a game with Radeon Overlay. Before running a game, disable fullscreen optimization with game's exe file properties. Like this picture...
Also cdisable Windows Game Bar.
The good old Intel driver vs Radeon driver conflict. Even though you uninstalled the Intel graphics control panel, Windows probably installed a new driver version that is causing the issue. Check from device manager what version of the driver it is. If you do not use the iGPU, disable it from BIOS. Or you can use DDU to disable Windows from installing drivers from Windows update. Or try to disable it from device manager. Not sure if the latter works.
I followed this video How to Fix Radeon Software Host Application High CPU Usage - YouTube apparently there was a folder missing in my Video folder called Radeon ReLive so I had to create it then stop and restart the Radeon services hope this helps.