Depends on your graphics card.
Radeon™ R9 Fury, R9 300, and R7 300 Series
Radeon™ R9 200, R7 200, R5 300, R5 240, HD 8500 - HD 8900, and HD 7700 – HD 7900 Series
Yes, sorry. The drivers were new and I couldn't find a lot of information about it, but I read that yes, they are ending the support for Windows 8.1 They say to try Windows 7 drivers "AS IS" but they do not work for me. They do install, say BETA, but they do not have Enhanced Sync. I did try the Windows 10 version as well, but it could not find my video card. I assume that's a driver issue. Oh well. I can still upgrade to 10 if I want to.
There's no more Windows 8/8.1 drivers with 17.7.2, no matter what graphics card you have. Here's the Release Notes: Radeon Software Crimson ReLive Edition 17.7.2 Release Notes
You won't see Windows 8.1 in there anymore:
Unlike what it shows in 17.7.1:
Don't you mean "Downgrade to Windows 10"?
I am really disappointed that the new 17.2.2 GPU Driver is not supported on Windows 8.1.
I see no RX580 or Vega drivers on Windows 8.1.
Nvidia are still supporting Windows 8.1 64bit drivers on the GTX 780Ti I am using on this machine whilst I was/am "Waiting for Vega".
I do have a Windows 10 OS just to run DX12 so I guess I can try the new driver on that but that is not my OS of choice.
I still had been running Windows 8.1 64bit when I needed to.
Having said that ...
It seems like more telemetry patches have been applied to Windows 8.1 to make it behave more like Windows 10.
I am seeing very high CPU use frequently in Windows 8.1. Often in the range of 10 ~ 20%.
That's without running any applications and Norton Antivirus on Silent Mode.
I am seeing ridiculously high CPU utilization when running Mozilla Firefox(100%) / Google Chrome(85%) YouTube video.
The Audio Playback is set to 8bit CD Quality, so the Audio playback should not be a reason for such high CPU use.
I have run all sorts of Virus Checking including MalwareBytes, Norton, 360 total Security, etc etc. etc and no joy. Nothing found.
My machine is running with all the latest patches, and has been checked for proper installation.
I am hoping AMD will put more effort into Linux Drivers and Vulkan Support.
Please pick a Linux Distro to support heavily (Centos or Ubuntu perhaps).
It would be nice to see a Radeon Crimson type GUI and features running on Linux.
GPU passthrough is working on some Linux distributions with Ryzen Processors so Users should be able to run Windows 10 in a virtual machine on Linux just for gaming.
I've never tried Windows 10 before today. The Cortana thing is annoying, and I had to turn a lot of settings off. Other than that, it's pretty smooth.
Not sure about your usages... Google Chrome eats my RAM but not my CPU. Only 8% when I watch video on HD. Your 10-20% seems normal IMO.
I upgraded to 10 just for the Enhanced Sync.